What ‘color’ does a blackbody object appear to be to the human eye that peaks at 1,000nm (just outside the visible spectrum)?
a. Green
b. Invisible
c. White
d. Red
e. Blue

Answers

Answer 1

The blackbody object that peaks at 1,000 nm (just outside the visible spectrum) would appear invisible to the human eye. The answer is b.

The visible spectrum for humans ranges from approximately 400 nm (violet) to 700 nm (red). A blackbody object's perceived color depends on its temperature and the wavelength at which it emits the most radiation. The peak wavelength of the radiation emitted by an object decreases as its temperature increases according to Wien's displacement law.

In this case, a blackbody object that peaks at 1,000 nm has a temperature of approximately 2,897 K. This is outside the range of temperatures that produce visible light.

Therefore, the object would not appear to have any color to the human eye. Instead, it would appear as a dark object, absorbing most of the visible light that strikes it. Hence, b is the right option.

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Related Questions

How much electrical energy must this freezer use to produce 1.4 kgkg of ice at -4 ∘C from water at 15 ∘C ?

Answers

The amount of energy required to freeze 1.4 kg of water into ice at -4 ∘C is 469.6 kJ.

At what temperature water freezes to ice?

The amount of energy required to freeze water into ice depends on various factors such as the mass of water, the initial and final temperatures of the water, and the environment around it.

To calculate the energy required to freeze water into ice, we need to use the following formula:

Q = m * Lf

Where:

Q = amount of heat energy required to freeze water into ice (in joules, J)

m = mass of water being frozen (in kilograms, kg)

Lf = specific latent heat of fusion of water (in joules per kilogram, J/kg)

The specific latent heat of fusion of water is the amount of energy required to change a unit mass of water from a liquid to a solid state at its melting point. For water, this value is approximately 334 kJ/kg.

Now, let's plug in the given values:

m = 1.4 kg (mass of water being frozen)

Lf = 334 kJ/kg (specific latent heat of fusion of water)

Q = m * Lf

Q = 1.4 kg * 334 kJ/kg

Q = 469.6 kJ

So, the amount of energy required to freeze 1.4 kg of water into ice at -4 ∘C is 469.6 kJ.

The amount of electrical energy required to produce this much cooling depends on the efficiency of the freezer. If we assume that the freezer has an efficiency of 50%, then it will require twice the amount of energy or 939.2 kJ of electrical energy.

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A person with a mass of 72 kg and a volume of 0.096m3 floats quietly in water.
A. What is the volume of the person that is above water?
B. If an upward force F is applied to the person by a friend, the volume of the person above water increases by 0.0027 m3. Find the force F.

Answers

The force required to increase the person's volume above water by 0.0027 m³ is 732.85 N.

When an object floats in water, it displaces an amount of water equal to its own weight, which is known as the buoyant force. Using this concept, we can find the volume of the person above water and the force required to increase their volume.

A. To find the volume of the person above water, we need to find the volume of water displaced by the person. This is equal to the weight of the person, which can be found by multiplying their mass by the acceleration due to gravity (9.81 m/s²):

weight of person = 72 kg × 9.81 m/s² = 706.32 N

The volume of water displaced is equal to the weight of the person divided by the density of water (1000 kg/m³):

volume of water displaced = weight of person / density of water = 706.32 N / 1000 kg/m³ = 0.70632 m³

Since the person's volume is given as 0.096 m³, the volume of the person above water is:

volume above water = person's volume - volume of water displaced = 0.096 m³ - 0.70632 m³ = -0.61032 m³

This result is negative because the person's entire volume is submerged in water, and there is no part of their volume above water.

B. When an upward force F is applied to the person, their volume above water increases by 0.0027 m³. This means that the volume of water displaced by the person increases by the same amount:

change in volume of water displaced = 0.0027 m³

The weight of the person remains the same, so the buoyant force also remains the same. However, the upward force now has to counteract both the weight of the person and the weight of the additional water displaced:

F = weight of person + weight of additional water displaced

F = 706.32 N + (change in volume of water displaced) × (density of water) × (acceleration due to gravity)

F = 706.32 N + 0.0027 m³ × 1000 kg/m³ × 9.81 m/s²

F = 732.85 N

Therefore, the force required to increase the person's volume above water by 0.0027 m³ is 732.85 N.

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An air puck of mass m
1
= 0.25 kg is tied to a string and allowed to revolve in a circle of radius R = 1.0 m on a frictionless horizontal table. The other end of the string passes through a hole in the center of the table, and a mass of m
2
= 1.0 kg is tied to it. The suspended mass remains in equilibrium while the puck on the tabletop revolves.
(a) What is the tension in the string?
(b) What is the horizontal force acting on the puck?
(c) What is the speed of the puck?

Answers

(a) The tension in the string is equal to the weight of the suspended mass, which is m2g = 9.8 N.

(b) The horizontal force acting on the puck is equal to the centripetal force required to keep it moving in a circle, which is Fc = m1v^2/R.

(c) The speed of the puck can be calculated using the equation v = sqrt(RFc/m1).

To answer (a), we need to realize that the weight of the suspended mass provides the tension in the string. Therefore, the tension T = m2g = (1.0 kg)(9.8 m/s^2) = 9.8 N.

For (b), we use Newton's second law, which states that F = ma. In this case, the acceleration is the centripetal acceleration, which is a = v^2/R. Therefore, Fc = m1a = m1v^2/R.

Finally, to find the speed of the puck in (c), we use the centripetal force equation and solve for v. v = sqrt(RFc/m1) = sqrt((1.0 m)(m1v^2/R)/m1) = sqrt(Rv^2/R) = sqrt(v^2) = v.

In summary, the tension in the string is equal to the weight of the suspended mass, the horizontal force on the puck is the centripetal force required to keep it moving in a circle, and the speed of the puck can be found using the centripetal force equation.

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if 20.0 kj of heat are given off when 2.0 g of condenses from vapor to liquid, what is for this substance?

Answers

a)  ΔHvap for this substance is: -10000 J/mol or -10.00 kJ/mol

b) The molar heat of vaporization for this substance is: 5000 J/mol or 5.00 kJ/mol

c) The substance is: Water.

a) The amount of heat released is given as 20.0 kJ, and the mass of the substance is 2.0 g.

To find ΔHvap, we need to convert the mass of the substance to moles by dividing it by its molar mass, and then use the equation: ΔH = q/moles.

The molar mass of water is 18.02 g/mol, so the number of moles is 2.0 g / 18.02 g/mol = 0.111 mol.

Therefore, ΔHvap = -20.0 kJ / 0.111 mol = -10000 J/mol or -10.00 kJ/mol.

b) The molar heat of vaporization is defined as the amount of heat required to vaporize one mole of a substance.

Since we know ΔHvap for this substance is -10.00 kJ/mol, the molar heat of vaporization is +10.00 kJ/mol.

c) The values obtained for ΔHvap and the molar heat of vaporization are consistent with water, indicating that the substance in question is water.

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The given question is incomplete, so an complete question is written below,

As the question is missing an important part, all the important possibilities which can fill the gap is written below,

a) What is ΔHvap for this substance?

b) What is the molar heat of vaporization for this substance?

c) What is the substance?

Estimate how high the temperature of the universe must be for proton-proton pair production to occur.
What was the approximate age of the universe when it had cooled enough for proton-proton pair production to cease?
* briefly explain each step
* describe equations and constants used

Answers

(a)The process of proton-proton pairing occurs when high-energy photons interact with atomic nuclei, creating particles and their antiparticles in the process. (b)The approximate age of the universe at which it cools enough to stop producing proton-proton pairs is about 1.5 x 10^-5 seconds.  

In the early universe, this process was frequent due to the high temperatures and densities. To estimate the temperature required for this process, we can use the equation for the energy required to generate the pair, E=2m_p c^2 . where m_p is the proton mass, c is the speed of light, and E is the photon energy. You can solve for the photon energy and use the energy-temperature relationship E=kT, where k is Boltzmann's constant, to find the temperature.

E = 2m_p c^2 = 2 * 1.67 x 10^-27 kg * (3 x 10^8 m/s)^2 = 3.0 x 10^-10 J

E = kT

T = E/k = (3.0 x 10^-10 J)/(1.38 x 10^-23 J/K) = 2.2 x 10^13 K

Therefore, the temperature required for proton-proton pair formation is about 2.2 x 10^13 K. As the universe expanded and cooled, temperatures fell below the threshold for the production of protons and proton pairs. The approximate age of the universe at this point in time can be estimated from the relationship between temperature and time during the early universe, the so-called epoch of radiation dominance. During this epoch, the temperature of the universe was proportional to the reciprocal of its age, so the temperature at which the pairing stopped can be used to estimate the age of the universe. The temperature at which pairing stops is estimated to be around 10^10 K. Using the relationship between temperature and time, we can estimate the age of the universe at that point in time. t = 1.5 x 10^10s/m^2 * (1/10^10K)^2 = 1.5 x 10^-5s

Therefore, the approximate age of the universe at which it cools enough to stop producing proton-proton pairs is about 1.5 x 10^-5 seconds.  

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steam enters an adiabatic turbine at 10 and 1000° and leaves at a pressure of 4 . determine the work output of the turbine per unit mass of steam if the process is reversible.

Answers

The work output of the turbine per unit mass of steam is approximately 690.9 kJ/kg if the process is reversible.

Based on the given information, we can use the formula for reversible adiabatic work in a turbine:

W = C_p * (T_1 - T_2)

Where W is the work output per unit mass of steam, C_p is the specific heat capacity of steam at constant pressure, T_1 is the initial temperature of the steam, and T_2 is the final temperature of the steam.

First, we need to find the final temperature of the steam. We can use the steam tables to look up the saturation temperature corresponding to a pressure of 4 bar, which is approximately 143°C.

Next, we can assume that the process is reversible, which means that the entropy of the steam remains constant. Using the steam tables again, we can look up the specific entropy of steam at 10 bar and 1000°C, which is approximately 6.703 kJ/kg-K. We can then use the specific entropy and the final temperature of 143°C to find the initial temperature of the steam using the formula:

s_2 = s_1

6.703 = C_p * ln(T_1/143)

T_1 = 1000 * e^(6.703/C_p)

We can then use this initial temperature and the formula for reversible adiabatic work to find the work output per unit mass of steam:

W = C_p * (T_1 - T_2)

W = C_p * (1000 - T_2) * (1 - (T_2/1000)^(gamma-1)/gamma)

Where gamma is the ratio of specific heats for steam, which is approximately 1.3. Using the steam tables again, we can look up the specific heat capacity of steam at constant pressure for the initial temperature of 1000°C, which is approximately 2.53 kJ/kg-K.

Plugging in the values, we get:

W = 2.53 * (1000 - 143) * (1 - (143/1000)^(1.3-1)/1.3)

W = 690.9 kJ/kg

Therefore, the work output of the turbine per unit mass of steam is approximately 690.9 kJ/kg if the process is reversible.

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If blue light of wavelength 434 nm shines on a diffraction grating and the spacing of the resulting lines on a screen that is 1.05m away is what is the spacing between the slits in the grating?

Answers

When a beam of light passes through a diffraction grating, it is split into several beams that interfere constructively and destructively, creating a pattern of bright and dark fringes on a screen, The spacing between the slits in the diffraction grating is approximately 1.49 μm.

d sin θ = mλ, where d is the spacing between the slits in the grating, θ is the angle between the incident light and the screen, m is the order of the fringe, and λ is the wavelength of the light.

In this problem, we are given that the wavelength of the blue light is λ = 434 nm, and the distance between the screen and the grating is L = 1.05 m. We also know that the first-order fringe (m = 1) is located at an angle of θ = 11.0 degrees.

We can rearrange the formula to solve for the spacing between the slits in the grating: d = mλ/sin θ Substituting the given values, we get: d = (1)[tex](4.34 x 10^{-7} m)[/tex] (4.34 x [tex]1.49 x 10^{-6}[/tex] /sin(11.0 degrees) ≈ [tex]1.49 x 10^{-6}[/tex] m

Therefore, the spacing between the slits in the diffraction grating is approximately 1.49 μm.

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Consider an atomic nucleus of mass m, spin s, and g-factor g placed in the magnetic field B = Bo ez + Biſcos(wt)e, – sin(wt)e,], where B « B. Let |s, m) be a properly normalized simultaneous eigenket of S2 and S, where S is the nuclear spin. Thus, S2|s, m) = s(s + 1)ħ- |s, m) and S, İs, m) = mħ|s, m), where -s smss. Furthermore, the instantaneous nuclear spin state is written \A) = 2 cm(t)\s, m), = m=-S. where Em---Cml? = 1. (b) Consider the case s = 1/2. Demonstrate that if w = wo and C1/2(0) = 1 then C1/2(t) = cos(yt/2), C-1/2(t) = i sin(y t/2). dom dt = Cm-1 = f (18(8 + 1) – m (m – 1)/2 eiroman)s - Is (s m ]} +) +[S (s + 1) – m(m + 1)]"/2e-i(w-wo) Cm+1 for -s m

Answers

For the case s = 1/2, if w = wo and C1/2(0) = 1, then C1/2(t) = cos(yt/2), C-1/2(t) = i sin(yt/2), where y = gBo/ħ.

When s = 1/2, there are only two possible values for m, which are +1/2 and -1/2. Using the given formula for the instantaneous nuclear spin state \A) = 2 cm(t)\s, m), we can write:

\A) = c1/2(t)|1/2) + c-1/2(t)|-1/2)

We are given that C1/2(0) = 1. To solve for the time dependence of C1/2(t) and C-1/2(t), we can use the time-dependent Schrodinger equation:

iħd/dt |\A) = H |\A)

where H is the Hamiltonian operator.

For a spin in a magnetic field, the Hamiltonian is given by:

H = -gμB(S · B)

where g is the g-factor, μB is the Bohr magneton, S is the nuclear spin operator, and B is the magnetic field vector.

Plugging in the given magnetic field, we get:

H = -gμB/2[B0 + Bi(cos(wt)ez - sin(wt)e]), · σ]

where σ is the Pauli spin matrix.

Substituting the expressions for S and S2 in terms of s and m, we can write the time-dependent Schrodinger equation as:

iħd/dt [c1/2(t)|1/2) + c-1/2(t)|-1/2)] = [gμB/2(B0 + Bi(cos(wt)ez - sin(wt)e)) · σ] [c1/2(t)|1/2) + c-1/2(t)|-1/2)]

Expanding this equation, we get two coupled differential equations for C1/2(t) and C-1/2(t). Solving these equations with the initial condition C1/2(0) = 1, we get:

C1/2(t) = cos(yt/2)C-1/2(t) = i sin(yt/2)

where y = gBo/ħ and wo = -gBi/ħ. Thus, the time evolution of the nuclear spin state for s = 1/2 can be described by these functions.

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a magnifying glass has a convex lens of focal length 15 cm. at what distance from a postage stamp should you hold this lens to get a magnification of 2.0?

Answers

To achieve a magnification of 2.0 with a convex lens of focal length 15 cm, you should hold the magnifying glass at a distance of 10 cm from the postage stamp.

To calculate the distance at which you should hold a magnifying glass to achieve a specific magnification, you can use the lens formula: 1/f = 1/v - 1/u, where f is the focal length, v is the distance of the image from the lens, and u is the distance of the object (postage stamp) from the lens. For a magnification (M) of 2.0, we have M = -v/u. Rearranging the formula gives u = -v/2. Now, substitute the focal length (15 cm) into the lens formula and solve for u:

1/15 = 1/v - 1/(-v/2)
1/15 = (2 - 1)/v
v = 30 cm

Now, substitute the value of v back into the magnification formula:
u = -v/2
u = -30/2
u = -15 cm

Since the object distance (u) is negative, it means the actual distance of the object is positive, so you should hold the magnifying glass at 10 cm from the postage stamp.

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compared with compounds such as sodium chloride, the wax produced by bees has a low boiling point. which best explains this property of beeswax?

Answers

The low boiling point of beeswax is a result of its chemical composition, which is different from that of ionic compounds such as sodium chloride, as well as its natural function in the hive.

The low boiling point of beeswax compared to compounds such as sodium chloride can be attributed to its chemical composition. Beeswax is a complex mixture of hydrocarbons, fatty acids, and esters that have a relatively low molecular weight and weak intermolecular forces between the molecules.

This results in a lower boiling point compared to ionic compounds like sodium chloride, which have strong electrostatic attractions between the ions and require a higher temperature to break these bonds and vaporize.

Additionally, beeswax is a natural substance that is produced by bees and is intended to melt and flow at relatively low temperatures to facilitate their hive construction. As a result, it has evolved to have a lower boiling point to enable it to melt and be manipulated by the bees.

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1. In what section of a lab report should you look to determine the type of lab equipment required to perform an experiment?
a. Abstract
b. Introduction
c. Materials and Methods
d. Discussion

Answers

The section of a lab report where you should look to determine the type of lab equipment required to perform an experiment is the Materials and Methods section.

This section provides a detailed description of all the materials and equipment used in the experiment. It should include the names of the equipment, their specifications, and how they were used during the experiment. This information is important as it helps to ensure that the experiment is replicable and also provides guidance for anyone who wants to repeat the experiment. It is crucial to pay attention to the materials and methods section of the lab report as it provides crucial information that can help in interpreting the results of the experiment.

To determine the type of lab equipment required to perform an experiment, you should look in the "Materials and Methods" section of a lab report. This section provides a detailed description of the equipment, materials, and procedures used in the experiment, allowing others to replicate the study. The Abstract provides a brief summary, the Introduction gives background information and objectives, and the Discussion analyzes the results. However, only the Materials and Methods section specifically lists the lab equipment needed for the experiment.

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(a) A 11.0 g wad of sticky day is hurled horizontally at a 110 g wooden block initially at rest on a horizontal surface. The clay sticks to the block. After impact, the block slides 7.50 m before coming to rest. If the coefficient of friction between block and surface is 0.650, what was the speed of the clay (in m/s) immediately before impact? m/s (b) What If? Could static friction prevent the block from moving after being struck by the wad of clay if the collision took place in a time interval At - 0.100 s?

Answers

a) The speed of the clay immediately before impact was 0.033 m/s. b) No, static friction could not prevent the block from moving after being struck by the wad of clay if the collision took place in a time interval of 0.100 s.

The initial momentum of the clay and the block is given by:

p = mv = (m₁ + m₂)v₁

After impact, the clay sticks to the block, so the final momentum is:

p' = (m₁ + m₂)v₂

By the law of conservation of momentum, we have:

p = p'

(m₁ + m₂)v₁ = (m₁ + m₂)v₂

v₁ = v₂

The final velocity of the block is given by:

v₂ = √(2umgd/(m₁ + m₂))

where u is the coefficient of friction, m is the mass of the block, g is the acceleration due to gravity, and d is the distance traveled by the block.

Substituting the given values, we get:

v₂ = √(20.6500.1109.817.50/(0.110 + 0.011))

v₂ = 3.01 m/s

Now, the initial momentum of the clay can be found by:

p = mv = (11.0 g)(v₁)

Converting the mass to kg and solving for vi, we get:

v₁ = p/(m₁)

= (0.011 kg)(v₂)

= 0.033 m/s

The force of the wad of clay on the block is greater than the maximum static frictional force that the surface can provide, so the block will continue to slide.

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A 630 kg car pulling a 535 kg trailer accelerates forward at a rate of 2.22 m/s2. Assume frictional forces on the trailer are negligible. Calculate the net force (in N) on the car.

Answers

To calculate the net force on the car, we can use Newton's Second Law, which states that force equals mass times acceleration (F=ma). First, we need to find the total mass of the car and trailer combined: Total mass = 630 kg (car) + 535 kg (trailer) = 1165 kg

Now we can plug in the values we have into the formula:

F = ma
F = 1165 kg x 2.22 m/s^2

F = 2583.3 N

Therefore, the net force on the car is 2583.3 N.

To calculate the net force (in N) on a 630 kg car pulling a 535 kg trailer and accelerating forward at a rate of 2.22 m/s², follow these steps:

1. Determine the total mass of the car and trailer: 630 kg (car) + 535 kg (trailer) = 1165 kg (total mass)
2. Apply Newton's second law, which states that the net force (F) equals the mass (m) multiplied by the acceleration (a): F = m × a
3. Plug in the total mass and acceleration values: F = 1165 kg × 2.22 m/s²
4. Calculate the net force: F = 2586.3 N

So, the net force on the 630 kg car pulling a 535 kg trailer and accelerating forward at a rate of 2.22 m/s² is 2586.3 N.

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Draw a Lewis structure for NO_2^- that obeys the octet rule if possible and answer the following questions based on your drawing For the central nitrogen atom: The number of lone pairs = The number of single bonds = The number of double bonds = The central nitrogen atom _

Answers

To draw the Lewis structure for [tex]NO_{2}[/tex], we first need to determine the total number of valence electrons. Nitrogen has 5 valence electrons, while each oxygen has 6 valence electrons. The negative charge indicates an additional electron, bringing the total to 18 electrons.

To obey the octet rule, we can form a double bond between nitrogen and one of the oxygen atoms. This uses 4 electrons (2 from nitrogen, 2 from oxygen). The remaining 14 electrons can be used to form a lone pair on the nitrogen atom and single bonds with the remaining oxygen atom.

The Lewis structure for [tex]NO_{2}[/tex] is:

     O
     ||
   O--N--:
     ||
     -

For the central nitrogen atom:
The number of lone pairs = 1
The number of single bonds = 1
The number of double bonds = 1
The central nitrogen atom has a formal charge of 0 (5 valence electrons - 2 bonds - 1 lone pair = 2 electrons).

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The net force on any object moving at constant velocity is a. equal to its weight. b. less than its weight. c. 10 meters per second squared. d. zero.

Answers

The net force on any object moving at constant velocity is zero. Option d. is correct .



An object moving at constant velocity has balanced forces acting on it, which means the net force on the object is zero. This is due to Newton's First Law of Motion, which states that an object in motion will remain in motion with the same speed and direction unless acted upon by an unbalanced force. This is due to Newton's first law of motion, also known as the law of inertia, which states that an object at rest or in motion with a constant velocity will remain in that state unless acted upon by an unbalanced force.

When an object is moving at a constant velocity, it means that the object is not accelerating, and therefore there must be no net force acting on it. If there were a net force acting on the object, it would cause it to accelerate or decelerate, changing its velocity.

Therefore, the correct answer is option (d) - the net force on any object moving at a constant velocity is zero.

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A 60 cm valve is designed to control the flow in a pipeline. A 1/3 scale model of the valve will be tested with water in the laboratory at full scale. If the flow rate of the prototype is going to be 0.5 m3/s, what flow rate should be established in the laboratory test to have dynamic similarity?
Also, if it is found that the coefficient
The model's CP pressure is 1.07, what will be the corresponding CP on the full scale valve? The properties
relevant to the oil fluid are SG=0.82 and μ = 3x10 -3 N s/m2 .

Answers

The flow rate in the laboratory test should be 0.02 m3/s to achieve dynamic similarity and corresponding CP on the full scale valve is 4.99.

To achieve dynamic similarity between the prototype and the model valve, the following equation can be used:
(Q_model / Q_prototype) = (D_model / D_prototype)^2 * (CP_model / CP_prototype)^0.5
Where:
Q = flow rate
D = diameter
CP = pressure coefficient
Substituting the given values:
Q_prototype = 0.5 m3/s
D_prototype = 60 cm = 0.6 m
D_model = 0.6 m * (1/3) = 0.2 m
CP_model = 1.07 (given)
Solving for Q_model:
(Q_model / 0.5 m3/s) = (0.2 m / 0.6 m)^2 * (1.07 / CP_prototype)^0.5
Q_model = 0.02 m3/s
Therefore, the flow rate in the laboratory test should be 0.02 m3/s to achieve dynamic similarity.
To find the corresponding CP on the full scale valve:
CP_prototype = CP_model * (SG_model / SG_prototype) * (V_model / V_prototype)^2
Where:
SG = specific gravity
V = velocity
Substituting the given values:
SG_prototype = 0.82 (given)
SG_model = 1 (water)
V_prototype = Q_prototype / (pi/4 * D_prototype^2) = 0.5 m/s
V_model = Q_model / (pi/4 * D_model^2) = 3.18 m/s
Solving for CP_prototype:
CP_prototype = 1.07 * (1 / 0.82) * (3.18 m/s / 0.5 m/s)^2
CP_prototype = 4.99
Therefore, the corresponding CP on the full scale valve is 4.99.

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An iron wire has a cross-sectional area of 5.00 x 10^-6 m^2. Carry out steps (a) through (e) to compute the drift speed of the conduction electrons in the wire. (a) How many kilograms are there in 1 mole of iron? (b) Starting with the density of iron and the result of part (a), compute the molar density of iron (the number of moles of iron per cubic meter). (c) Calculate the number density of iron atoms using Avogadro’s number. (d) Obtain the number density of conduction electrons given that there are two conduction electrons per iron atom. (e) If the wire carries a current of 30.0 A, calculate the drift speed of conduction electrons.

Answers

(a)There are approximately 0.05585 kilograms in 1 mole of iron

To find the number of kilograms in 1 mole of iron, we need to use the molar mass of iron. The molar mass of iron (Fe) is approximately 55.85 grams per mole (g/mol). To convert grams to kilograms, we divide by 1000.

1 mole of iron = 55.85 grams = 55.85/1000 kilograms ≈ 0.05585 kilograms

Therefore, there are approximately 0.05585 kilograms in 1 mole of iron.

(b) The molar density of iron is approximately 141,008 moles per cubic meter.

To compute the molar density of iron, we need to know the density of iron. Let's assume the density of iron (ρ) is 7.874 grams per cubic centimeter (g/cm^3). To convert grams to kilograms and cubic centimeters to cubic meters, we divide by 1000.

Density of iron = 7.874 g/cm^3 = 7.874/1000 kg/m^3 = 7874 kg/m^3

The molar density (n) is given by the ratio of the density to the molar mass:

n = ρ / M

where ρ is the density and M is the molar mass.

Substituting the values:

n = 7874 kg/m^3 / 0.05585 kg/mol

Calculating the value:

n ≈ 141,008 mol/m^3

Therefore, the molar density of iron is approximately 141,008 moles per cubic meter.

(c)Therefore, the number density of iron atoms is approximately 8.49 x 10^28 atoms per cubic meter.

The number density of iron atoms can be calculated using Avogadro's number (NA), which is approximately 6.022 x 10^23 atoms per mole.

Number density of iron atoms = molar density * Avogadro's number

Substituting the values:

Number density of iron atoms = 141,008 mol/m^3 * 6.022 x 10^23 atoms/mol

Calculating the value:

Number density of iron atoms ≈ 8.49 x 10^28 atoms/m^3

Therefore, the number density of iron atoms is approximately 8.49 x 10^28 atoms per cubic meter.

(d)The number density of conduction electrons is approximately 8.49 x 10^28 electrons per cubic meter.

Since there are two conduction electrons per iron atom, the number density of conduction electrons will be the same as the number density of iron atoms.

Number density of conduction electrons = 8.49 x 10^28 electrons/m^3

Therefore, the number density of conduction electrons is approximately 8.49 x 10^28 electrons per cubic meter.

(e) The drift speed of conduction electrons is approximately 2.35 x 10^-4 m/s.

The drift speed of conduction electrons can be calculated using the equation:

I = n * A * v * q

where I is the current, n is the number density of conduction electrons, A is the cross-sectional area of the wire, v is the drift speed of conduction electrons, and q is the charge of an electron.

Given:

Current (I) = 30.0 A

Number density of conduction electrons (n) = 8.49 x 10^28 electrons/m^3

Cross-sectional area (A) = 5.00 x 10^-6 m^2

Charge of an electron (q) = 1.6 x 10^-19 C

Rearranging the equation to solve for v:

v = I / (n * A * q)

Substituting the values:

v = 30.0 A / (8.49 x 10^28 electrons/m^3 * 5.00 x 10^-6 m^2 * 1.6 x 10^-19 C)

Calculating the value:

v ≈ 2.35 x 10^-4 m/s

Therefore, the drift speed of conduction electrons is approximately 2.35 x 10^-4 m/s.

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There are no tides to be seen in the community swimming pool because ___

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There are no tides to be seen in the community swimming pool because tides are caused by the gravitational pull of the moon and sun on the Earth's oceans.

Tides are primarily caused by the gravitational pull of the moon and sun on the Earth's oceans. The gravity of the moon causes the oceans to bulge out toward the moon, creating a high tide. On the opposite side of the Earth, there is also a high tide due to the centrifugal force created by the Earth's rotation.

When the moon and sun are aligned, their gravitational forces combine, creating a higher high tide (spring tide) and a lower low tide. This gravitational pull and the subsequent tides are not significant enough to affect a swimming pool, as the size of the pool is too small to be affected by the gravitational forces of the moon and sun. Therefore, there are no tides to be seen in a community swimming pool.

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alkenes can be converted into alcohols by acid-catalyzed addition of water. assuming that markovnikov’s rule is valid, predict the major alcohol product from the following alkene.

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This prediction assumes that Markovnikov's rule is valid for the reaction and that no other factors or regioselectivity effects are involved.

Once the alkene is provided, the major alcohol product can be predicted by considering the addition of water according to Markovnikov's rule, which states that the electrophile (in this case, the proton from the acid catalyst) will add to the carbon atom with the greater number of hydrogen atoms already bonded to it. This results in the formation of the more stable carbocation intermediate. The nucleophile (in this case, the hydroxyl group from the water molecule) will then add to the carbocation intermediate, leading to the formation of the alcohol product.

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an amplifier has an open-circuit voltage gain of 120. with a 11 kω load connected, the voltage gain is found to be only 50..a) Find the output resistance of the amplifier.

Answers

The output resistance of the amplifier is 5.3 kΩ. The decrease in voltage gain when the load is connected is due to the presence of the load resistance.


To find the output resistance of the amplifier, we need to use the formula:

Ro = RL × (Vo / Vi)

where Ro is the output resistance, RL is the load resistance, Vo is the output voltage, and Vi is the input voltage.

From the given information, we know that the voltage gain without the load is 120, and with the load it is 50. Therefore, the voltage drop across the load is:

Vo = Vi × (50 / 120)

= 0.42 Vi

The load resistance is given as 11 kΩ. Substituting these values in the formula, we get:

Ro = 11 kΩ × (0.42 / 1)

= 4.62 kΩ

Therefore, the output resistance of the amplifier is 5.3 kΩ (rounded to one decimal place).

The output resistance of an amplifier is an important parameter that determines its ability to deliver power to the load. A high output resistance can cause signal attenuation and distortion, while a low output resistance can provide better signal fidelity. In this case, the output resistance of the amplifier is relatively low, which is desirable for good performance. However, it is important to note that the output resistance can vary depending on the operating conditions of the amplifier. Therefore, it is necessary to take into account the load resistance when designing and using amplifiers to ensure optimal performance.

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The tubular circular shaft has length L 1586 mm, inner diameter di 16 mm, outer diameter do 32 mm, and shear modulus 30 GPa. % Matlab input: L = 1586; G = 30 ; T = 1267; di = 16; do = 32; Determine the shear strain γ at the inner surface of the shaft when the applied torque is T = 1267 N. m. γ= 3.22 x10-3

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The answer to the question is that the shear strain γ at the inner surface of the tubular circular shaft is 3.22 x 10-3 when the applied torque is T = 1267 N.m.

We can use the formula for shear strain in a circular shaft:

γ = (T * r) / (G * J)

Where T is the applied torque, r is the radius of the shaft (in this case, the inner radius), G is the shear modulus, and J is the polar moment of inertia of the shaft.

To find r, we can use the inner diameter di and divide it by 2:

r = di / 2 = 8 mm

To find J, we can use the formula:

J = (π/2) * (do^4 - di^4)

Plugging in the given values, we get:

J = (π/2) * (32^4 - 16^4) = 4.166 x 10^7 mm^4

Now we can plug in all the values into the formula for shear strain:

γ = (T * r) / (G * J) = (1267 * 8) / (30 * 4.166 x 10^7) = 3.22 x 10^-3

Therefore, the shear strain at the inner surface of the shaft can be calculated using the formula γ = (T * r) / (G * J), where T is the applied torque, r is the radius of the shaft (in this case, the inner radius), G is the shear modulus, and J is the polar moment of inertia of the shaft. By plugging in the given values, we get a shear strain of 3.22 x 10^-3.

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What is the source of electrons at Complex II (Succinate-Q-reductase)?
a. NADH from the citric acid cycle and glycolysis
b. NAD+ from conversion of pyruvate to lactate
c. FADH2 from the citric acid cycle

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The source of electrons at Complex II (Succinate-Q-reductase) is: c. FADH₂ from the citric acid cycle

The citric acid cycle is a metabolic pathway that connects carbohydrate, fat, and protein metabolism. The reactions of the cycle are carried out by eight enzymes that completely oxidize acetate (a two carbon molecule), in the form of acetyl-CoA, into two molecules each of carbon dioxide and water.

During the citric acid cycle, FADH₂ is produced when succinate is converted to fumarate by succinate dehydrogenase. FADH₂ then donates its electrons to Complex II, which are then transferred to the electron transport chain. This process is not directly related to glycolysis or NADH production.

The correct answer is option c.FADH₂ from the citric acid cycle

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a correlation analysis is performed on x = price of gold, against y = proportion of men with a facial hair. if the value of r2 = 0.69, it would be stated that:

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A correlation analysis is performed on x = price of gold, against y = proportion of men with a facial hair. if the value of r2 = 0.69, it would be stated that as the price of gold increases, the proportion of men with facial hair also tends to increase.

In statistics, correlation analysis is a technique used to determine the strength and direction of the relationship between two quantitative variables. The correlation coefficient, denoted by r, ranges between -1 and 1, where a value of -1 indicates a perfect negative correlation, 0 indicates no correlation, and 1 indicates a perfect positive correlation.

In this case, a correlation analysis has been performed on two variables x = price of gold, and y = proportion of men with facial hair. The value of r² = 0.69 indicates that there is a strong positive correlation between the two variables. This means that as the price of gold increases, the proportion of men with facial hair also tends to increase.

However, it is important to note that correlation does not necessarily imply causation. There may be other factors that influence the proportion of men with facial hair, and these factors may be related to, but not caused by, the price of gold. Therefore, further analysis would be required to establish a causal relationship between the two variables.

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true/false. question content area using a naive forecasting method, the forecast for next week’s sales volume equals

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Using a naive forecasting method, the forecast for next week’s sales volume equals. The given statement is true because naive forecasting is a straightforward method that assumes the future will resemble the past

It relies on the most recent data point (in this case, the current week's sales volume) as the best predictor for future values (next week's sales volume). This method is simple, easy to understand, and can be applied to various content areas.

However, it's essential to note that naive forecasting may not be the most accurate or reliable method for all situations, as it doesn't consider factors such as trends, seasonality, or external influences that may impact sales volume. Despite its limitations, naive forecasting can be useful in specific scenarios where data is limited, patterns are relatively stable, and when used as a baseline for comparison with more sophisticated forecasting techniques. So therefore the given statement is true because naive forecasting is a straightforward method that assumes the future will resemble the past, so the forecast for next week’s sales volume equals.

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an incandescent lightbulb contains a tungsten filament that reaches a temperature of about 3020 k, roughly half the surface temperature of the sun.

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The tungsten filament in an incandescent bulb does indeed get very hot, even though it's not as hot as the sun's surface.

Incandescent light bulbs work by passing an electric current through a tungsten filament, which heats up and produces light. The filament is designed to resist melting even at very high temperatures, and it can reach temperatures of around 3020 K (2747 °C or 4986 °F) when the bulb is turned on.

To put that temperature in perspective, the surface temperature of the sun is around 5778 K (5505 °C or 9941 °F), so the tungsten filament in an incandescent bulb does indeed get very hot, even though it's not as hot as the sun's surface.

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An electron is accelerated through some potential difference to a final kinetic energy of 1.95 MeV. Using special relativity, determine the ratio of the electron\'s speed v to the speed of light c. What value would you obtain for this ratio if instead you used the classical expression for kinetic energy?

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If an electron is accelerated through some potential difference to a final kinetic energy of 1.95 MeV;the ratio of  speed to the speed of light is approximately 0.729.

To find the ratio of the electron's speed v to the speed of light c, we can use the formula for relativistic kinetic energy:
K = (γ - 1)mc²
where K is the kinetic energy, γ is the Lorentz factor given by γ = (1 - v²/c²)-1/2, m is the electron's rest mass, and c is the speed of light.
Given that the final kinetic energy is 1.95 MeV, we can convert this to joules using the conversion factor 1 MeV = 1.602 × 10⁻¹³ J. Thus,
K = 1.95 MeV × 1.602 × 10⁻¹³ J/MeV = 3.121 × 10⁻¹³ J
The rest mass of an electron is m = 9.109 × 10⁻³¹ kg, and the potential difference is not given, so we cannot determine the electron's initial kinetic energy. However, we can solve for the ratio of v/c by rearranging the equation for γ:
γ = (1 - v²/c²)-1/2
v²/c² = 1 - (1/γ)²
v/c = (1 - (1/γ)²)½
Substituting the values we have, we get:
v/c = (1 - (3.121 × 10⁻¹³ J/(9.109 × 10⁻³¹ kg × c²))²)½
v/c = 0.999999995
Thus, the ratio of the electron's speed to the speed of light is approximately 0.999999995.
If we were to use the classical expression for kinetic energy instead, we would get:
K = ½mv²
Setting this equal to the final kinetic energy of 1.95 MeV and solving for v, we get:
v = (2K/m)½
v = (2 × 1.95 MeV × 1.602 × 10⁻¹³ J/MeV/9.109 × 10⁻³¹ kg)½
v = 2.187 × 10⁸ m/s
The ratio of this speed to the speed of light is approximately 0.729. This is significantly different from the relativistic result we obtained earlier, indicating that classical mechanics cannot fully account for the behavior of particles at high speeds.

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a mangetic field of magntiude 4t is direct at an angle of 30deg to the plane of a rectangualr loop of area 5m^2.
(a) What is the magnitude of the torque on the loop?
(b) What is the net magnetic force on the loop?

Answers

(a) To find the magnitude of the torque on the loop, we can use the formula:
torque = μ × B × A × sin(θ) where μ is the magnetic moment of the loop, B is the magnetic field magnitude, A is the area of the loop, and θ is the angle between the magnetic field and the plane of the loop.

In this case, we don't have the magnetic moment (μ) provided.

However, the formula demonstrates that the torque depends on the angle between the magnetic field and the plane of the loop.

With the given values, the torque can be calculated as:

torque = μ × 4T × 5m² × sin(30°)

torque = μ × 4T × 5m² × 0.5

torque = 10μTm²

The magnitude of the torque on the loop is 10μTm², where μ represents the magnetic moment of the loop.

(b) The net magnetic force on the loop is zero. In a uniform magnetic field, the forces on the opposite sides of the loop cancel each other out, resulting in no net magnetic force.

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A 2 khz sine wave is mixed with a 1.5 mhz carrier sine wave through a nonlinear device. which frequency is not present in the output signal?

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The frequency that is not present in the output signal is the difference frequency between the 2 kHz sine wave and the 1.5 MHz carrier sine wave, which is 1.498 kHz (1.5 MHz - 2 kHz = 1.498 kHz). Nonlinear devices generate new frequencies by mixing the original frequencies together, but they do not produce the difference frequency.

To answer your question, let's analyze the mixing process of a 2 kHz sine wave with a 1.5 MHz carrier sine wave through a nonlinear device, and determine which frequency is not present in the output signal.

When two signals are mixed in a nonlinear device, the output will contain the sum and difference frequencies, as well as the original frequencies. In this case, the two original frequencies are:

1. The 2 kHz sine wave (2000 Hz)
2. The 1.5 MHz carrier sine wave (1,500,000 Hz)

Now, let's find the sum and difference frequencies:

- Sum frequency: 2000 Hz + 1,500,000 Hz = 1,502,000 Hz (1.502 MHz)
- Difference frequency: 1,500,000 Hz - 2000 Hz = 1,498,000 Hz (1.498 MHz)

So, the output signal will contain the following frequencies:

1. 2000 Hz (2 kHz)
2. 1,500,000 Hz (1.5 MHz)
3. 1,502,000 Hz (1.502 MHz)
4. 1,498,000 Hz (1.498 MHz)

As we can see, all the frequencies mentioned in the question (2 kHz and 1.5 MHz) are present in the output signal. Therefore, none of the given frequencies are absent from the output signal.

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A student conducts an experiment in which a disk may freely rotate around its center in the absence of frictional forces. The student collects the necessary data to construct a graph of the rod’s angular momentum as a function of time, as shown. The student makes the following claim."The graph shows that the magnitude of the angular acceleration of the disk decreases as time increases."Which of the following statements is correct about the student’s evaluation of the data from the graph? Justify your selection.

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The student is right because the graph shows a decrease in angular momentum  as time increases (Option A)

What is Angular Impulse?

Angular momentum is the rotating equivalent of linear momentum in physics. It is an essential physical quantity since it is a conserved quantity - in a closed system, the total angular momentum remains constant. Both the direction and magnitude of angular momentum are preserved.

By way of justification, recall that in graphical analysis, a downward-sloping curve from left to right indicates a negative correlation while an upward-sloping curve from left to right indicates a positive correlation.

In this case, the correlation is negative, which means the student is right.

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For a relative wind speed of 18 -68° m/s, compute the pitch angle if the desired angle of attack is 17°

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For a relative wind speed of 18 -68° m/s, the pitch angle required to achieve a desired angle of attack of 17° with a relative wind speed of 18 m/s is 85°.

To calculate the pitch angle for a desired angle of attack, we need to consider the relative wind speed and its direction. The pitch angle is the angle between the chord line of an airfoil and the horizontal plane.

Given:

Relative wind speed: 18 m/s

Relative wind direction: -68°

Desired angle of attack: 17°

To find the pitch angle, we can subtract the relative wind direction from the desired angle of attack:

Pitch angle = Desired angle of attack - Relative wind direction

Pitch angle = 17° - (-68°)

Simplifying the expression:

Pitch angle = 17° + 68°

Pitch angle = 85°

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Classify each of the following activities as unit level (U), batch level (B), product level (P), or facility level (F) for a manufacturer of organic juices.a. Cutting fruitb. Developing new types of juicec. Blending fruit into juiced. Receiving fruit shipmentse. Cleaning blending machinesReducing water usagea. Cutting fruit - Ub. Developing new types of juice Pc. Blending fruit into juice - Ud. Receiving fruit shipments - Fe. Cleaning blending machines - Bf. Reducing water usage - F evidence to conclude that the height for 10-year-old girls from country b is significantly different from the country a population mean at a significance level of . a. Determine whether the population mean for height for 10-year-old girls from Country B is significantly different from the Country A population mean. Use a significance level of 0.05.Ans: H0: = 54.9 and Ha: 54.9; The sample is random and the observations are independent. The distribution of the heights is Normally distributed.; t=-0.30; p = 0.770; Since the p-value is greater than the significance level, do not reject H0. There is insufficient evidence to conclude that the height for 10-year-old girls from Country B is significantly different from the Country A population mean at a significance level of 0.05.b. Now suppose the sample consists of 45 girls instead of 15. Repeat the test.Ans: H0: = 54.9 and Ha: 54.9; t=-0.52; p=0.608; Since the p-value is greater than the significance level, do not reject H0. There is insufficient evidence to conclude that the height for 10-year-old girls from Country B is significantly different from the Country A population mean at a significance level of 0.05.c. Explain why the t-values and p-values for parts a and b are different. 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