Solution :
A refrigerator is a heat engine running backwards with its main aim is to extract heat from the cold reservoir. When the engine running backwards is used to exhaust or give out hot air into a hot reservoir is known as a heat pump.
Given :
Coefficient of performance of the heat pump, COP = 3
We know COP of heat pump is K [tex]$=\frac{Q_h}{W_{in}}$[/tex]
a). Therefore the COP can also be written as :
[tex]$COP=\frac{T_h}{T_h-T_c}$[/tex]
[tex]$=\frac{Q_h}{W_{in}}$[/tex]
[tex]$=\frac{Q_h}{P_{in}}$[/tex]
∴ [tex]$3=\frac{15}{P_{in}}$[/tex]
[tex]$P_{in }=\frac{15}{3}$[/tex]
= 5 kW
b). The heating cost in a home of one month with a 15 kW electric heater can be calculated as :
1 dollar = 40 MJ (given)
∴ $1 / 40000 kWh (15 kW)(200 x 3600 s)
= $ 270
Violet light (410 nm) and red light
(685 nm) pass through a diffraction
grating with d = 3.33 x 10-6 m. What is
the angular separation between them
for m = 2?
Answer:10.03
Explanation:acellus
A sound has a higher pitch than a bell. Which quantity must also be higher in this sound than in the bell?
O amplitude
O frequency
O wavelength
O speed
Answer:
frequency
Explanation:
The frequency must also be higher in this sound than in the bell because for high pitch the frequency must be high.
What is the frequency?It is defined as the number of waves that crosses a fixed point in one second, known as frequency. The unit of frequency is per second.
We have:
A sound has a higher pitch than a bell.
As we know, the sound has a high pitch if the vibration frequency is high, and a low pitch if the vibration frequency is low.
Thus, the frequency must also be higher in this sound than in the bell because for high pitch the frequency must be high.
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1 point
Nuclear equations like the one below show "parent" and "daughter” nuclei.
What is the mathematical relationship between the superscripts on the
left-hand side and the superscripts on the right-hand side of the nuclear
equation?
27
27
0
12 Mg
13 AL +
je
Answer:
Mg- 27 means isotope with 12 protons and 15 neutrons.
Also 27 is mass number which express sum of protons and neutrons.
In nucleus one neutrn decays to electron and proton. Mass number remain same but Al-27 nucleus contain 13 protons and 14 neutrons. Electron is ejected out from nucleus.
A man rides a bike along a straight road at a constant speed for 5 minmin, then has a flat tire. He stops for 5 minmin to repair the flat, but then realizes he cannot fix it. He continues his journey by walking the rest of the way at a constant speed, which takes him another 10 min.
Required:
Use the particle model to draw a motion diagram of the man for the entire motion described here. Number the dots in order, starting with zero.
Which formula is used to find an object's acceleration?
The answer is:
C. a = △t/ △vThe formula used to find an object's acceleration is a = Δv / Δt.
What is acceleration?Acceleration is the rate of change of the velocity of an object with respect to time. It is a vector quantity.
The equation for acceleration is
a = Δv / Δt
where a is acceleration,
Δv is the change in velocity,
Δt is the amount of time it took for that change to occur.
The unit is [tex]\frac{m}{s^{2} }[/tex].
There are two ways by which an object can accelerate. One is to change the speed and other one is to change the direction. Even you can change both at same time.
If not changing any of them then object can not accelerate.
Some of examples of acceleration are
Turning a corner at high speed as turning changes the direction and giving rise to acceleration.Slowing or speeding a car is acceleration as speed is changing. So acceleration happens.Falling from the bridge. Here acceleration equals to gravitational acceleration.
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what's is the best definition of AVERAGE SPEED?
Answer:
The average speed is the distance travelled divided by the time taken: Average speed=Distance travelledTime taken.
E._____________________
15-letter words that start with e
electromagnetic
experimentation
electrophoresis
excommunication
extracurricular
ethnomusicology
epichlorohydrin
exemplification
electrodynamics
experimentalism
extralinguistic
electromyograph
electronegative
electrodialysis
ecclesiasticism
encephalography
electrokinetics
electropositive
electroanalysis
enterobacterium
eclaircissement
econometricians
econometrically
ecocatastrophes
ecclesiological
ecclesiologists
echinodermatous
echocardiograms
ecophysiologies
easygoingnesses
egocentricities
eggheadednesses
egregiousnesses
efficaciousness
effortfulnesses
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effectivenesses
egalitarianisms
educationalists
enterobacterial
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enterogastrones
enjoyablenesses
entomologically
entrepreneurial
envenomizations
environmentally
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encephalographs
encephalitogens
encephalopathic
enantiomorphism
enantiomorphous
emulsifications
endoparasitisms
endonucleolytic
endocrinologies
endocrinologist
enfranchisement
electroacoustic
electrification
electrochemical
electroanalyses
electrophoretic
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electrophoreses
electromyograms
electrodialytic
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expressionistic
exponentiations
A person pulls a box across the floor with a rope. The rope makes an angle of 40 degrees tot he horizontal, and a total of 125 newtons of force is applied. How much work is done if the box is pulled for 25 meters?
Answer:
The angle formed of the rope with the surface = 40°
Force applied = 125Newtons
The displacement covered by the box =25metres
W= FDcos theta
[125×40×cos(40°) ] Joules
= [ (3125×0.76604444311)]Joules
= 2393.88888472 joules(ans)
Hope it helps
A circuit with 220 voltage is supplied with a fuse of 10 ampere.How many bulbs of 100 watt can be safely used in the circuit
SOMONE PLEASE HELP ASAP!!!!
Answer:
Both waves travel at same speed in vacuum.
Explanation:
Infrared waves and ultraviolet waves both have different wavelengths.
Energy is dependent upon wavelength:
[tex]E = \frac{hc}{\lambda}[/tex]
where,
E = Energy
h = Plank's Constant
c = speed of light
λ = wavelength
Hence different wavelength means different energies.
The frequency is dependent upon the wavelength through the formula:
v = fλ
where,
v = speed of the wave
f = frequency of the wave
λ = wavelength
Hence, different wavelength requires different frequency, while the speed remains same, which is equal to the speed of light for electromagnetic radiations.
Therefore, the correct option is:
Both waves travel at same speed in vacuum.
Tritium and helium-3 have the same number of nucleons, but tritium has one proton and two neutrons whereas helium-3 has two protons and one neutron. Without doing a calculation, decide which nucleus has a greater binding energy. Explain. (Select all that apply.)
a. This happens in part because the tritium nucleus has greater Coulombic repulsion.
b. This happens in part because the helium-3 nucleus has greater Coulombic repulsion between nucleons.
c. This happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
d. Helium-3 is more stable.
e. This happens in part because the helium-3 nucleus has fewer neutrons.
f. Tritium is more stable.
Answer:
Tritium is more stable.
This happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
Explanation:
The binding energy is the energy that holds nucleons together in the nucleus. It depends on the number of nucleons present in the nucleus. The greater the number of nucleons, the greater the binding energy.
Also, the more the number of neutrons in a nucleus, the greater the nuclear forces. Helium-3 has only one neutron while tritium has two neutrons. The extra neutron in tritium enhances the nuclear forces hence tritium has a greater binding energy than Helium-3
Tritium is more stable.this happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
What is binding energy?
The binding energy is the energy that holds nucleons together in the nucleus. It depends on the number of nucleons present in the nucleus.
The greater the number of nucleons, the greater the binding energy.Also, the more the number of neutrons in a nucleus, the greater the nuclear forces.
Helium-3 has only one neutron while tritium has two neutrons. The extra neutron in tritium enhances the nuclear forces hence tritium has greater binding energy than Helium-3
Thus tritium is more stable.this happens in part because the tritium nucleus has an extra neutron enhancing the nuclear forces.
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An initially uncharged sphere is on an insulated stand and isolated in a chamber. The charge on the sphere is monitored as a beam of monochromatic light shines on the sphere. Initially nothing happens. The wavelength of the light is slowly decreased. When the wavelength reaches a certain value, a positive charge is suddenly measured on the sphere. The wavelength is then held constant, and the charge continues to increase at a constant rate. The intensity of the beam is then increased without the wavelength being changed, and the rate of increase of the charge becomes greater.
Required:
a. In a coherent paragraph-length response, describe the cause of the charge on the sphere and the changes in the observations about the charge, in terms of physics principles.
b. An electron in the chamber is moving with speed 2×10^5m/s when it collides with a positron (a particle identical to an electron except for the sign of its charge) moving with the same speed in the opposite direction. The particles annihilate each other. How much energy is released due to the annihilation?
c. In another experiment, a beam of electrons with uniform wavelength λe is incident on a slit, where the width of the slit is much larger than λe. A detector is placed near the slit, but no diffraction pattern is observed. What change should be made that would result in a diffraction pattern? Indicate why this change is the one needed.
Answer:
a) E = K + Φ, b) ΔE = 1.64 10⁻¹³ J., c) λ = a
Explanation:
a) In this case it is an example of the photoelectric effect that was correctly described by Einstein assuming that the light ray is composed of a series of particles called photons, each one with an energy given by the Planck equation
E = h f
c = λ f
substituting
E = h c /λ
We can see from this equation that as the wavelength of the ray decreases the energy of each photon increases, the moment arrives that the energy is sufficient to remove an electron from the sphere, thus leaving an unbalanced positive charge, this description explains why the positive charge appears on the sphere; the minimum wavelength to remove an electron is
E = K + Φ
if K = 0
E =Φ
where fi is the work function of the material.
When the intensity of the ray increases according to Eintein's description, the number of photons increases, so if the number of photons increases, the number of shocks and the number of electrons expelled increases, therefore the unbalanced positive charge also increases.
b) the energy released in collision is the sum of the energy of each particle
for the electron
E = K + m c² = (pc) ² + (m c²) ²
where the moment is
p = γ m u
γ = [tex]\sqrt{1- (\frac{u}{c})^2 }[/tex]
γ = [tex]\sqrt {1- ( \frac{2 \ 10^5}{3 \ 10^8 })^2 } = \sqrt{1- (6.67 \ 10 ^{-4)^2 }[/tex]
γ ≅ 1
in this case since the speed of the particles is much less than the speed of light,
E = (m u) ² + (m c²) ²
E = m² (u² + c²)
E = 9.1 10⁻³¹ [(2 10⁵) ² + (3 10⁸) ²
E = 9.1 10⁻³¹ 9 10¹⁶
E = 8.2 10⁻¹⁴ J
the positron has an energy of equal magnitude, so when the two particles annihilate the energy change is
ΔE = 2E
ΔE = 2 (8.2 10⁻¹⁴)
ΔE = 1.64 10⁻¹³ J.
c) the expression that describes the diffraction process is
a sin θ = m λ
sin θ = m λ/ a
where a is the width of the slit and m in diffraction order
The greatest value that the sine function can have is 1
1 = m λ / a
λ = a / m
therefore we can see that to see the diffraction phenomenon the width of the slit must be greater than or equal to the wavelength
If you build a circuit with 3 D batteries, what is the voltage of the circuit?
A) 3 volts
B) 4.5 volts
C) 3 Amps
D) 4.5 Ohms
Answer:
a
Explanation:
Answer:
d
Explanation:
What did Europeans, africans and Americans trade as a result for the Colombian exchange
A. Railroad engineering ideas
B. Computer technology
C. Film production techniques
D. Agricultural knowledge
Also under the subject I meant to put social studies not physics.
Answer: Railroad engineering ideas
Calculate the force of gravity on the 1-kg mass if it were 3.2x10^6 m above Earth's surface that is, if it were one and a half
Earth radii from Earth's center).
Answer:
F= 4.3N
the question (for seo and search engine optimization to get this question to the top)
Calculate the force of gravity on the 1-kg mass if it were 3.2×106m above Earth's surface (that is, if it were one and a half Earth radii from Earth's center).
F= 4.3N
Answer:
Recuerda que la Ley de gravitación universal de Newton puede enunciarse así: “Toda partícula de
materia en el universo atrae a todas las demás partículas con una fuerza que es directamente
proporcional a las masas de las partículas e inversamente proporcional al cuadrado de la distancia que
las separa”. Ley que se puede expresar simbólicamente de la siguiente forma:
2
1 2
d
m m F ⋅ ∝
Podemos expresar la proporcionalidad de la ley de gravitación universal en forma de una ecuación
exacta introduciendo la constante de proporcionalidad G, llamada constante de gravitación universal:
2
1 2
d
m m F G ⋅ = ⋅ donde
2
3. A dog walks 12 meters to the east and then 16 meters back to the west.
For this motion, what is the distance moved?
What is the magnitude and direction of the displacemeni?
Answer:
[tex]distance = 16 + 12 \\ = 28 \: meters \\ \\ displacement = {}^{ + } 12 + {}^{ - } 16 \\ = - 4 \: meters \\ magnitude = > |s| = 4 \: meters[/tex]
ANSWER ASAP: Keiyah and Sam canoe down the Guadalupe. As Keiyah pulls the oar through the water, the water against the oar is pushing the canoe forward. This is an example of Newton's:
First Law
Second Law
Third Law
Law of Conservation of Mass
- Newton's first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
- His second law defines a force to be equal to change in momentum (mass times velocity) per change in time. Momentum is defined to be the mass m of an object times its velocity V.
- His third law states that for every action (force) in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A.
Now which law do you think is happening in the problem?
The answer will be Newton's third law.
A man is weighed 450N runs up a flight of
Staires consisting of 25 steps each 10cm height
20s calculate the power
Answer:
56.25 watts
Explanation:
P = F * d / t
P = Power (it's an unknown at this point).
F = 450 N
d = 25 steps each 10 cm = 25 steps 0.1 m/step = 2.5 m
t = 20 s
Solution
P = 450 * 2.5 / 20
P = 1125/20
P = 56.25
By how many times would the gravitational force between two objects decrease if the distance between the two objects was tripled?
Answer:
If the separation distance between any two objects is tripled (increased by a factor of 3), then the force of gravitational attraction is decreased by a factor of 9 (3 raised to the second power).
Need Help please!!!! What is the velocity of a 100.0 kg football player running with a momentum of 590 kg^ * m/s ?
Answer:
5.9 m/sExplanation:
The velocity of the football player can be found by using the formula
[tex]v = \frac{p}{m} \\ [/tex]
p is the momentum
m is the mass
We have
[tex]v = \frac{590}{100} = 5.9 \\ [/tex]
We have the final answer as
5.9 m/sHope this helps you
What materials are difficult to charge because electrons easily flow through them?
Answer:
Conductors
Explanation:
An organ pipe is 116 cm long. Determine the fundamental and first three audible overtones if the pipe is (a) closed at one end, and (b) open at both ends.
Answer:
(a) when the pipe is closed at one end;
F₀ = 73.92 Hz
F₁ = 221.76 Hz
F₂ = 369.6 Hz
F₃ = 517.44
(b) when the pipe is open at both ends;
F₀ = 147.85 Hz
F₁ = 295.7 Hz
F₂ = 443.55 Hz
F₃ = 591.4 Hz
Explanation:
Given;
length of the pipe, L = 116 cm = 1.16 m
speed of sound in air, v = 343 m/s
The formula below will be used to determine the different frequencies of the pipe at different wavelengths
[tex]F = \frac{V}{\lambda}[/tex]
where;
F is frequency
λ is wavelength
(a) when the pipe is closed at one end;
Wavelength for fundamental frequency;
L = Node -------> Antinode
L = λ/4
λ = 4L
the fundamental mental frequency;
[tex]F_0 = \frac{V}{4L} = \frac{343}{4 \times 1.16} = 73.92 \ Hz[/tex]
Wavelength for first overtone or audible frequency;
L = Node -----> Node + Node ----> Antinode
L = λ/2 + λ/4
L = 3λ/4
λ = 4L/3
[tex]F_1 = \frac{V}{4L/3} = 3(\frac{V}{4L} ) = 3F_0 = 3 (73.92) = 221.76 \ Hz[/tex]
Thus, the next two audible frequencies will be multiple of next consecutive odd numbers after 3 (i.e 5 and 7);
F₂ = 5F₀ = 5(73.92) = 369.6 Hz
F₃ = 7F₀ = 7(73.92) = 517.44 Hz
(b) when the pipe is open at both ends;
Wavelength for fundamental frequency;
L = Antinode ----> Node + Node -----> Antinode
L = λ/4 + λ/4
L = λ/2
λ = 2L
the fundamental frequency;
[tex]F_0 = \frac{V}{2L} = \frac{343}{2\times 1.16} = 147.85 \ Hz[/tex]
The first three audible overtones will be multiples of the 3 consecutive positive integers after 1 (i.e 2, 3, 4)
F₁ = 2F₀ = 2(147.85) = 295.7 Hz
F₂ = 3F₀ = 3(147.85) = 443.55 Hz
F₃ = 4F₀ = 4(147.85) = 591.4 Hz
Is it more fun on a swing with low or high amplitude? Explain.
You have a 6.00 V power supply, and
a 30.0 ohm and a 75.0 ohm resistor.
Find the current flowing out of the
battery if the resistors are connected
in parallel.
Answer: 0.28 A
Explanation:
Answer:
.28
Explanation:
Acellus
PLEASE HELP ME ASAP!!!!
Which planet USED TO HAVE WATER?
Answer:
Earth btw im 12
Explanation:
Earth is the only known planet to have bodies of liquid water on its surface. Europa is thought to have subsurface liquid water. Scientists hypothesize that Europa's hidden ocean is salty, tidal, and causes its ice surface to move, resulting in large fractures
Answer:
Earth
Explanation:
is the only known planet to have bodies of liquid water on its surface
Pls help! Tysm!!! :D
Answer:
Slowing a bike by applying the brkaes is an xmaple of acceleration
Explanation:
What is the period of a wave that completes 3 waves in 2 seconds?
P = 3÷2
= 1.5
Explanation:
hope it helps
A 1.5-kg ball is throw at 10 m/s. What is the balls momentum?
Answer : The momentum of ball is, 15 kg.m/s
Explanation :
Momentum : It is defined as the motion of a moving body. Or it is defined as the product of mass of velocity of an object.
Formula of momentum is:
where,
p = momentum = ?
m = mass = 1.5 kg
v = velocity = 10 m/s
Now put all the given values in the above formula, we get:
Therefore, the momentum of ball is 15 kg.m/s
Which ones are correct??
Answer:
blanket:thermal conductivity
as it conduct heat.
aquarium glass:transparency
as light can be transfered from one side to
another.