Answer:
η = 0.84 = 84%
Explanation:
The efficiency of the man can be given by the following formula:
η = output/input
where,
η = efficiency of man = ?
output = potential energy gain of the block = mgh
input = work done by man = Fd
Therefore,
[tex]\eta = \frac{mgh}{Fd}[/tex]
where,
m = mass of block = 225 kg
g = acceleration due to gravity = 9.81 m/s²
h = height gained by block = 1.2 m
F = force exerted by man = 315 N
d = distance covered by man = 10 m
Therefore,
[tex]\eta = \frac{(225\ kg)(9.81\ m/s^2)(1.2\ m)}{(315\ N)(10\ m)}[/tex]
η = 0.84 = 84%
Following the big bang gaseous clouds condensed together to form the first stars in the universe. What is the attractive force that causes the gas to
come together?
O Energy
Electromagnetism
O Dark Matter
O Gravity
Answer:
Gravity
gravity pulled the gasses together over long period of time
i love u whoosever seeing my question
What's the difference between heat and temperature?
Answer:
Heat is the transfer of thermal energy between molecules within a system and is measured in Joules (J). It measures how energy moves or flows. Temperature is the average kinetic energy of molecules within a material or system and is measured in Celcius (°C), Kelvin (K), Fahrenheit (°F), or Rankine (R).
Joe first focuses his attention (and his eyes) on the tree. The focal length of the cornea-lens system in his eye must be __________ the distance between the front and back of his eye. View Available Hint(s) Joe first focuses his attention (and his eyes) on the tree. The focal length of the cornea-lens system in his eye must be __________ the distance between the front and back of his eye. greater than less than equal to
Answer: The focal length of the cornea-lens system in his eye must be LESS THAN the distance between the front and back of his eye.
Explanation:
The human eye the front part of the eye is the CORNEA. This is the tough white transparent part of the eye that helps in the refraction of light rays. While the backside of the eye is the RETINA. This is the part of the eye when images are focused.
When a normal eye is at rest, parallel rays from a distant object are focused on the retina. The ability of the eye - lens to focus points at different distances on the retina is known as accomodation. The adjustment of the eye lens to focus objects of varying distances is brought about by the ciliary muscles. The have the ability to change the shape of the eye which leads to change in focal length.
When a person with normal vision looks at a distant object at infinity, the lens brings parallel rays to focus on the retina. Thus, the furthest point which the eye can see distinctly is called the far point of the eye and it's infinity for a normal eye. But Joe was able to focus his eye on the tree, meaning that the tree was within his near point. This is the nearest point at which an object is clearly seen. Therefore, when the effective focal length of the cornea-lens system changes, it changes the location of the image of any object in one's field of view.
The formula length x width x height is used to calculate the volume of a type of
A
gas.
B
solid.
C
liquid.
D
plasma.
Answer:
D
Explanation:
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Select the correct answer. In a given chemical reaction, the energy of the products is greater than the energy of the reactants. Which statement is true for this reaction? A. Energy is absorbed in the reaction. B. Energy is released in the reaction. C. No energy is transferred in the reaction. D. Energy is created in the reaction. E. Energy is lost in the reaction.
Imagine a truck crashes into a building. What kind of sound wave does this make?
Thr wave of sound that makes the truck is vibration
In a two-slit experiment using coherent light, the distance between the slits and the screen is 1.10 m, and the distance between the slits is 0.100 mm. If the first-order bright fringe is measured to be 3.40 cm from the centerline, what is the wavelength of the light?
Answer:
Wavelength of the light = 3.09 meter
Explanation:
Given:
Distance between slits and the screen = 1.1 meter
Distance between slits = 0.1 mm
First-order bright fringe = 3.40 cm from centerline
Find:
Wavelength of the light
Computation:
Distance between slits = 0.1 mm
Distance between slits = 0.0001 meter
First-order bright fringe = 3.40 cm from centerline = 0.034 meter
Wavelength of the light = [(Distance between slits)(First-order bright fringe)]/Distance between slits and the screen
Wavelength of the light = [(0.0001)(0.034)] / 1.1
Wavelength of the light = [(0.0001)(0.034)] / 1.1
Wavelength of the light = 3.09 meter
A block of wood has mass 4kg, what is the density of the wood if the mass of water is 3kg and its volume is half that of the block of the block of wood ?
A plane electromagnetic wave, with wavelength 5 m, travels in vacuum in the positive x direction with its electric vector E, of amplitude 229.1 V/M, directed along y axis. What is the time-averaged rate of energy flow in watts per square meter associated with the wave
Answer:
Explanation:
E₀ = 229.1 V/m
E = E₀ / √2 = 229.1 / 1.414 = 162 V/m
B = E / c ( c is velocity of em waves )
= 162 / (3 x 10⁸) = 54 x 10⁻⁸ T
rate of energy flow = ( E x B ) / μ₀
= 162 x 54 x 10⁻⁸ / 4π x 10⁻⁷
= 69.65 W per m².
If at a particular instant and at a certain point in space the electric field is in the x-direction and has a magnitude of 5.00 V/mV/m, what is the magnitude of the magnetic field of the wave at this same point in space and instant in time
Answer:
the magnitude of the magnetic field of the wave is 16.7 nT
Explanation:
Given the data in the question;
Electric field E = 5.00 V/m
we know that the expression for the electric field of an electromagnetic wave in terms if magnetic field is;
E = cB
where c is the speed of light ( 3 × 10⁸ m/s )
and B is the magnetic field
so we solve for the magnetic field
B = E / c
we substitute in the value of E and c
B = (5.00 V/m) / (3 × 10⁸ m/s)
B = 1.67 × 10⁻⁸ T
B = 1.67 × 10⁻⁸ T [tex]( \frac{1nT}{10^{-9}T} )[/tex]
B = 16.7 nT
Therefore, the magnitude of the magnetic field of the wave is 16.7 nT
If the frequency of a light wave is doubled, what happens to the wavelength of the wave?
Answer:
If the frequency is doubled, the wavelength is only half as long. 3. ... As the frequency slows down, the wavelength increases.
what is relative density
Answer:
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material.
Explanation:
15 cm
Gas
Mercury
If the atmospheric pressure is 750 mmHg, what is the pressure of the gas in:
(i) mmHg
you multiply 15cm by 750 mmhg
A p-n junction diode is, as the name suggests, an electronic device that is made up of a p-type semiconductor and an n-type semiconductor joined together.
a. True
b. False
Answer:
a. True
Explanation:
When a p-type semiconductor is placed adjacent to an n-type semiconductor the common plane thus formed is termed as P-N Junction or P-N Junction Diode.
The diode is formed by melting both p-type and n-type semiconductors through a special manufacturing process called "Thermo-Compression Proces".
The P-N junction has a property of one-way conduction. It means it only allows the current to pass through it in one direction and the current flow is practically zero in the other direction. Thus, it can act as a diode. The p-side acts as the anode, while the n-side acts as the cathode.
Hence, the correct option is:
a. True
What cycle moves carbon from one part of the Earth to another
Answer:
The cycle that moves carbon from one part of the Earth to another is called the carbon cycle.
Explanation:
The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Since our planet and its atmosphere form a closed environment, the amount of carbon in this system does not change. Where the carbon is located — in the atmosphere or on Earth — is constantly in flux.
On Earth, most carbon is stored in rocks and sediments, while the rest is located in the ocean, atmosphere, and in living organisms. These are the reservoirs, or sinks, through which carbon cycles. Carbon is released back into the atmosphere when organisms die, volcanoes erupt, fires blaze, fossil fuels are burned, and through a variety of other mechanisms. In the case of the ocean, carbon is continually exchanged between the ocean’s surface waters and the atmosphere, or is stored for long periods of time in the ocean depths.
Humans play a major role in the carbon cycle through activities such as the burning of fossil fuels or land development. As a result, the amount of carbon dioxide in the atmosphere is rapidly rising; it is already considerably greater than at any time in the last 800,000 years.
Will give brainliest! 50 points!!!
When the polarity of a moving magnet through a coil doubles the electromagnetic field _________.
A. Increases
B. Decreases
C. Stays the same
Answer:
C
Im not totally sure but that's what my science teacher taught me sorry if is wrong
What does the if statement in a macro do?
It changes the data type of the macro based on the results of a query.
It attaches the macro to a query or report prior to printing to make it readable.
It creates a control in a form and connects the macro to the control’s event property.
It defines a criterion that evaluates to true or false and specifies actions to take if it is true.
Answer:
It defines a criterion that evaluates to true or false and specifies actions to take if it is true.
Explanation:
EDGE2020
Answer:
D
Explanation:
EMERGENT please answer
Answer:
meaning i dont know sorry
True or False: Our food has potential energy?
Answer:
True
Explanation:
just cuz
a box of mass 40kg is been drag along the floor by a rope inclined at 60degree to the horizontal, the frictional force between the box and the floor is 100N and the tension of the rope is 300N how much work is done in dragging the box through a distance of 4m
Answer:
Hopefully this is correct:
Given: m=40kg θ=60 to the horizontal
Ff to floor is 100N and Tension=300N
Find Work:
Given:
[tex]W=fd[/tex]
Where f= net force applied parallel to the block: Use cos(60)
=300cos(60)-100=50(4)=200J work
The table provided shows the masses and volumes of four liquids. A student has a mystery liquid with a density of 3 g/mL. Which liquid does the student have?
Liquid 1
Liquid 2
Liquid 3
Liquid 4
Answer: Liquid 2, if it's 3 g/mL and liquid 2 has 6gs and 2 mLs than it's 3g/mL
what is renewable and non-renewable energy?
Renewable resources:
A renewable resource is one that can be used repeatedly and does not run out because it is naturally replaced.
Nonrenewable resource:
A nonrenewable resource is a natural substance that is not replenished with the speed at which it is consumed. It is a finite resource.
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Answer:
Renewable energy includes solar, hydro, and wind energy. Non-renewable energy includes coal, gas, and oil.Explanation:
Renewable energy is useful energy that is collected from renewable resources, which are naturally replenished on a human timescale. A non-renewable resource is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption.
An object whose weight is 100 lbf experiences a decrease in kinetic energy of 500 ft-lbf and an increase in potential energy of 1500 ft-lbf. The initial velocity and elevation of the object, each relative to the surface of the earth, are 40 ft/s and 30 ft, respectively.
Required:
a. Find final velocity in ft/s.
b. Find final elevation.
Answer:
a) the final velocity is 35.75 ft/s
b) The final elevation is 45 ft
Explanation:
Given the data in the question;
Weight of object; W = 100 lbf
Change in kinetic energy; ΔE = 500 ft-lb
so
[tex]\frac{1}{2}[/tex]m[tex]v_i^2[/tex] - [tex]\frac{1}{2}[/tex]m[tex]v_f^2[/tex] = ΔE
[tex]\frac{1}{2}[/tex]m[tex]v_i^2[/tex] - [tex]\frac{1}{2}[/tex]m[tex]v_f^2[/tex] = 500
multiply both sides by 2
m[tex]v_i^2[/tex] - m[tex]v_f^2[/tex] = 1000
m( [tex]v_i^2[/tex] - [tex]v_f^2[/tex] ) = 1000
[tex]v_i^2[/tex] - [tex]v_f^2[/tex] = 1000/m
[tex]v_i^2[/tex] - [tex]v_f^2[/tex] = (1000)(g) / W
we know that, acceleration due to gravity g = 9.8 m/s² = 32.18 ft/s²
so we substitute
[tex]v_i^2[/tex] - [tex]v_f^2[/tex] = (1000)(32.18) / 100
[tex]v_i^2[/tex] - [tex]v_f^2[/tex] = (1000)(32.18) / 100
[tex]v_i^2[/tex] - [tex]v_f^2[/tex] = 32180 / 100
[tex]v_i^2[/tex] - [tex]v_f^2[/tex] = 321.8
since The initial velocity [tex]v_i[/tex] is given to be 40 ft/s;
(40)² - [tex]v_f^2[/tex] = 321.8
1600 - [tex]v_f^2[/tex] = 321.8
[tex]v_f^2[/tex] = 1600 - 321.8
[tex]v_f^2[/tex] = 1278.2
[tex]v_f[/tex] = √1278.2
[tex]v_f[/tex] = 35.75 ft/s
Therefore, the final velocity is 35.75 ft/s
b)
we know that;
change in potential energy is;
ΔP.E = mg( h[tex]_f[/tex] - h[tex]_i[/tex] )
given that; increase in potential energy; ΔP.E = 1500 ft-lbf
and mg = Weight = 100 lbf
we substitute
1500 = 100( h[tex]_f[/tex] - h[tex]_i[/tex] )
h[tex]_f[/tex] - h[tex]_i[/tex] = 1500 / 100
h[tex]_f[/tex] - h[tex]_i[/tex] = 15 ft
given that, elevation of the object; h[tex]_i[/tex] = 30 ft
h[tex]_f[/tex] - 30 ft = 15 ft
h[tex]_f[/tex] = 15 ft + 30 ft
h[tex]_f[/tex] = 45 ft
Therefore, The final elevation is 45 ft
HELPPP WILL MARK BRAINLIST What type of image is formed by a lens if m= 2.7?
A. The image is smaller than the object and is virtual.
B. The image is smaller than the object and is real.
C. The image is larger than the object and is real.
D. The image is larger than the object and is virtual.
Answer:
the answer is C
Explanation:
So, the formed image will be real and inverted.
Shadow is formed when an_____
object comes in the
way
of light.
Answer:
shadow is formed when an opaque object comes on path of light shadows are formed because light travels in a straight line and it can't pass through an opaque object
Answer:
Opaque object
Explanation:
Shadow forms when an opaque object comes in the way of light. Because opaque objects does not allow light to pass through them and light travels in a straight line. Hence a retreating figure of the same opaque object ,forms and it's black in colour without any detail just outline.
A 34-kg child runs with a speed of 2.8 m/s tangential to the rim of a stationary merrygo-round. The merry-go-round has a momentum of inertia of 510 kg*m2 and a radius of 2.31 m. When the child jumps onto the merry-go-round, the entire system begins to rotate. What is the angular speed of the system
Answer: [tex]0.43\ rad/s[/tex]
Explanation:
Given
Mass of child [tex]m=34\ kg[/tex]
speed of child is [tex]v=2.8\ m/s[/tex]
Moment of inertia of merry go round is [tex]I=510\ kg.m^2[/tex]
radius [tex]r=2.31\ m[/tex]
Conserving the angular momentum
[tex]\Rightarrow mvr=I\omega \\\Rightarrow 34\times 2.8\times 2.31=510\times \omega\\\\\Rightarrow \omega=\dfrac{219.912}{510}\\\Rightarrow \omega=0.43\ rad/s[/tex]
With a thunderstorm brewing, an electric field of magnitude 2.0 × 102 newtons/coulomb exists at a certain point in the earth’s atmosphere. If an electron at that point has a charge of -1.6 × 10-19 coulombs, what is the magnitude of the force on the electron as a result of the electric field?
A.
2.0 × 10-6 newtons
B.
3.2 × 10-17 newtons
C.
5.8 × 105 newtons
D.
6.4 × 10-3 newtons
E.
1.7 × 104 newtons
Answer:
The correct option is (b).
Explanation:
Given that,
Electric field, [tex]E=2\times 10^2\ N/C[/tex]
We need to find the magnitude of the force on the electron as a result of the electric field.
We know that, the electric force is given by :
[tex]F=qE\\\\=1.6\times 10^{-19}\times 2\times 10^2\\\\F=3.2\times 10^{-17}\ N[/tex]
So, the required force on the electron is equal to [tex]3.2\times 10^{-17}\ N[/tex].
What is the magnification of a real image if the image is 15.0 cm from a lens and the object is 60.0 cm from the lens?
Answer:
soluble
Explanation:
Answer:
-0.25
Explanation:
Gravitationally, how does the alignment of the sun, earth, and moon being in a straight line influence earth's tides?
Answer:
The alignment of the sun, earth, and moon being in a straight line causes very low and extra-high, low and high tides respectively due to the additive effect of the solar tide on the lunar tide.
Explanation:
Tides can be defined as the rise and fall of water level in water bodies such as lakes and oceans due to the gravitational force of attraction exerted by the moon on earth. The side closest to the moon creates a bulge of water known as high tide. Low tides are generally experienced when a sea level is not within the bulge.
Generally, the gravitational pull of the Moon cause visible changes on planet Earth's surface.
This ultimately implies that, the pull of the Moon's gravity causes high and low tides on planet Earth's surface.
The various types of ocean tides based on the position of the Earth, Moon and the Sun are;
I. Neap tides.
II. Spring tides.
III. Low tide.
IV. High tide.
V. Brown tide.
VI. Rip tide.
VII. Red tide.
Generally, the alignment of the sun, earth, and moon being in a straight line causes very low and extra-high, low and high tides respectively due to the additive effect of the solar tide on the lunar tide. Thus, this alignment of the sun, earth, and moon being in a straight line gives rise to spring tides.