A blue train of mass 50 kg moves at 4 m/s toward a green train of 30 kg initially at rest. What is the initial momentum of the blue train?
A. 20 kgm/s
B. 200 kgm/s
C. 50 kgm/s
D. 0 kgm/s
Answer:
B. 200 kgm/s
Explanation:
The initial momentum of the blue train can be calculated using the formula:
p = mv
where p is the momentum, m is the mass, and v is the velocity.
The mass of the blue train is 50 kg and its velocity is 4 m/s. Therefore, the initial momentum of the blue train is:
p = 50 kg x 4 m/s = 200 kgm/s
Therefore, the initial momentum of the blue train is 200 kgm/s, which is option B.
Use the heating curve (Figure 1) to answer the question.
Temperature (°C)
200
150
100
50
0
-50
-100
-150
200 400 600 800 1000 1200
Energy (J)
What is the boiling point of the substance represented?
0
-100 °C
150 °C
-50 °C
50 °C
Answer:
Melting Point = -50 °C
Boiling Point = 50 °C
Explanation:
A heating curve displays a substance in its 3 states.
On the graph, each region where the slope is positive represents the substance as a solid, liquid, or gas.
When the slope is 0, this is the temperature point at which the substance's state of matter has changed (i.e., melting or boiling/vaporization point) – also known as a phase transition. Essentially, the 0 slope regions are where the substance is changing from one state of matter to the next.
(When the substance is being heated, it's absorbing energy, but when it reaches a phase transition point, the substance begins to consume energy to change its matter state. That's why the temperature doesn't go up while the substance's internal Energy increases.)
In (Figure 1), where 'x' is Energy (J) and 'y' is Temperature (°C):
Region A (0 J ≤ x ≤ 200 J):
The slope is positive, so the substance is in a constant matter state. Because it's the first sloped region, the substance is in its solid state from -100 °C to -50 °C.
Region B (200 J ≤ x 600 J):
The slope is 0, so the substance has reached a phase transition point. Because the previous region was when the substance was solid, that means that the temperature throughout Region B is the melting point at -50 °C.
Region C (600 J ≤ x ≤ 800 J):
The slope is positive so the substance is in a constant matter state. We've already identified when the substance was solid and when it melted, so now the substance is in its liquid state from -50 °C to 50 °C.
Region D (800 J ≤ x ≤ 900 J):
The slope is 0, and since the previous region was when the substance was a liquid, it's now reached its boiling point at 50 °C.
Region E (900 J ≤ x ≤ 1000 J):
The slope is positive, and we've previously identified all of the transition points and matter states except for one, so the substance is now in its gaseous state after reaching 100°C.
(Once a substance reaches its gaseous state, the Temperature/Energy ratio is constant.)
Researchers want to assess your intelligence. To do so, they have you
complete a short survey on which you indicate your favorite color. They ask
you to complete this survey multiple times, and you always answer the same
color. Unfortunately, one's favorite color has nothing to do with one's
intelligence. This research survey is best defined as:
This research survey is an example of a flawed or invalid measure of intelligence.
The research survey that is shown in this question can be defined as a poor measurement tool for assessing intelligence. One can easily identify that the researchers are measuring intelligence by asking about the favorite color of the personnel, which has nothing to do with the intelligence of the person. This survey lack validity which is essential to measure the intelligence of any personnel through a survey.
The survey also lacks reliability as it can't provide consistent results. If the intelligence of any personnel is somehow related to the intelligence of the person, answering the survey multiple times must give the same answer. This doesn't provide consistent result and lack reliability and realism.
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What type of circuit is shown
=When three resistors are connected in parallel, they form a parallel circuit. In a parallel circuit, each resistor is connected across the same two points, with the current split between the resistors.
In this configuration, the voltage across each resistor is the same, but the current through each resistor can be different. The total resistance of the circuit is calculated using the equation:
1/R_total = 1/R1 + 1/R2 + 1/R3
where R1, R2, and R3 are the resistance values of the individual resistors.
The total current in the circuit is equal to the sum of the currents through each resistor:
I_total = I1 + I2 + I3
where I1, I2, and I3 are the currents through each resistor.
The total power dissipated in the circuit can be calculated using the equation:
P_total = V² / R_total
where V is the voltage across the resistors.
In summary, when three resistors are connected in parallel, they form a parallel circuit, with each resistor connected across the same two points, and the current split between them. The total resistance, current, and power dissipated in the circuit can be calculated using the equations provided.
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Why did Izzy fall when playing tug of war? Responses he tripped he tripped balanced forces balanced forces he was pushed he was pushed unbalanced forces
Answer:
he tripped ballanced forces ballanced forces
what is the net charge when you rub a plastic ruler with fur
The net charge when you rub a plastic ruler with fur would be infinitesimal or zero
How to detect the net chargeThe effect of friction between a plastic ruler and fur is evident when electrons are transferred from the hairy surface to the ruler's plane, ending with the ruler possessing a negative charge while the fur taking on a positive one.
As a result, the whole system presents with a net charge that is negative it converges due to the excess electrons now found on the ruler. However, occasionally, the magnitude of this charge is very small, consequently making it difficult to probe without reliable technology or instruments.
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What is the definition of physical activity?
A.
a movement that stimulates your respiratory system
B.
a movement that causes perspiration
C.
a movement that results in the body’s use of energy
D.
a movement that requires little effort
Answer: The answer is C
Explanation: because I got it correct
C. A movement that results in the body's use of energy.
WHO has defined physical activity as any bodily movement that requires expenditure of energy.
Physical activity includes both exercise as well as integrated activities of one's daily routine.
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A mass of 10kg suspended on a steel rod of length 2m and radius 1mm what is the elongation of the rod beyond it's original length (Take E = 200*10^9 Newton per metre square
The elongation of the rod beyond its original length would be 2.5 mm.
Elongation calculationTo elongation of the rod can be deduced using the formula:
ΔL = FL / AE
where:
ΔL is the elongationF is the force appliedL is the original length of the rodA is the cross-sectional area of the rodE is Young's modulus of elasticity of the material.The cross-sectional area of the steel rod is given by:
A = π[tex]r^2[/tex]A = π[tex](0.001 m)^2[/tex] = 7.85 x [tex]10^{-7} m^2[/tex]The force applied to the rod:
F = mgF = 10 x 9.81 = 98.1 NThus:
ΔL = (98.1 x 2) / ((7.85 x [tex]10^{-7[/tex]) x (200 x [tex]10^9[/tex] ))
ΔL = 0.0025 m = 2.5 mm
In other words, the elongation of the steel rod beyond its original length is 2.5 mm.
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A megaphone amplifies sound by
all the above
increasing the range of frequencies that can be produced.
focusing sound energy into one specific direction.
spreading out the sound waves over a large area.
What is the magnitude of the force in coulomb's law when one of the charge is double
Answer: Doubled
Explanation:
HELP!!! You have two substances, both of which have the same boiling point (or attraction between their molecules).
The first substance is made from molecules that are small (just a few atoms bonded together), and the second substance is made from mol that are larger (many atoms bonded together).
How can it be possible for two such different molecules to yield substances with the same boiling point? Describe the kinds of intermolecu attractions that must be involved and any other properties of the molecules that could cause this result.
Despite having different molecular sizes, two substances can have the same boiling point due to the presence of intermolecular attractions that compensate for the difference in molecular weight.
What is the explanation for the above response?Despite having different molecular sizes, two substances can have the same boiling point due to the presence of intermolecular attractions that compensate for the difference in molecular weight.
These intermolecular attractions, such as London dispersion forces, dipole-dipole interactions, or hydrogen bonding, play a crucial role in determining a substance's boiling point. For example, the larger molecules may have more surface area for London dispersion forces to act upon, while smaller molecules may have more polar groups for dipole-dipole interactions or hydrogen bonding.
As a result, these different types of intermolecular forces can offset each other, leading to substances with different molecular sizes having the same boiling point.
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1.
Which of the following is not true concerning sound waves?
Sound requires a medium.
Sound waves are longitudinal waves.
MacBook Air
Sound requires a vibrating object.
Sound waves cause particles to vibrate perpendicular to
the direction of the wave.
Answer:
Sound waves cause particles to vibrate perpendicular to the direction of the wave.
Four point masses 2kg, 4kg, 6kg and 8kg are placed at the corners of Square ABCD of 2cm long respectively. Find the Position of centre of mass of the system from the corner A.
The position of the center of mass of the system from corner A is 4.3692cm.
To find the position of the center of mass of the system, we need to use the formula:
C.M. = (m1r1 + m2r2 + m3r3 + m4r4)/(m1 + m2 + m3 + m4)
where m1, m2, m3, and m4 are the masses of the four-point masses, and r1, r2, r3, and r4 are the distances of the point masses from the reference point (in this case, corner A).
Let's first find the distances of the four-point masses from corner A. We can see that the distance of the 2kg mass from corner A is 2 cm. The distance of the 4kg mass from corner A is the diagonal of a square of side 2 cm, which is sqrt(22 + 22) = 2.828 cm. Similarly, the distances of the 6kg and 8kg masses from corner A are also 2.828 cm.
Now, let's substitute the values in the formula:
C.M. = (2kg2cm + 4kg2.828cm + 6kg2.828cm + 8kg2.828cm)/(2kg + 4kg + 6kg + 8kg)
C.M. = (4cm + 11.312cm + 16.968cm + 22.624cm)/20kg
C.M. = 1.824cm + 0.5656cm + 0.8484cm + 1.1312cm
C.M. = 4.3692cm
Therefore, the position of the center of mass of the system from corner A is 4.3692cm.
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What is amplitude and phase in electrical and electronics circuit?
In electrical and electronics circuits, amplitude is the maximum value of a signal. This is known as the strength or intensity of the signal. Phase, can be seen as the timing relationship between two signals or waveforms. It tell the time it takes betwen the peaks or zero crossings of two waveforms
What more should you know about phase in electrical and electronics circuits?In electrical and electronics circuits, phase tell us about the the relationship between currents in different parts of the circuit, For example in AC circuits with multiple components.
We the amplitude and phase of signals in electrical and electronics circuits is understood, it becomes easier to design and analyz circuits, and can even be used for troubleshooting and maintaining them.
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Jeremiah is conducting an investigation about the water cycle. He is given the following materials:
a lamp
a glass jar that contains water
plastic wrap
Describe how Jeremiah can arrange these materials to create a model that shows the processes by which water is cycled from a lake into the atmosphere and back to the lake. Be sure to identify what each material represents in the model.
Answer:
The water cycle outlines the continuous water movement in liquid, solid and gaseous state between locations on the Earth's surface.
The glass jar represents the lake while the atmosphere is represented by the space above the water, and the sky is represented by the (clear) plastic wrap
Arrangement description and Processes;
The processes of the water cycle includes;
Evaporation;
Condensation
Precipitation
Sublimation
Runoff
Infiltration
The arrangement of the materials is as follows;
Place the glass jar (the lake) containing water and the lamp (the Sun) side by side, such that the lamp light shines on the water surface
Cover the glass jar by wrapping the plastic wrap (the sky) around it to prevent the escape of water vapor when the water is hot.
Switch on the lamp so that it heats the water by radiation heat transfer
Observed processes;
The processes demonstrated by the above experiment includes;
1) Evaporation: As the water in the glass jar becomes warmer, the level of the water in the jar can be observed to decrease slightly due to evaporation
2) Condensation: Fog formation, Clouds
When hotter, the water surface as seen through the clear plastic wrap becomes less clearer due to evaporation, and condensation of the vapor while floating above the water surface, similar to the clouds seen in the sky.
3. Precipitation: Rain;
The clear plastic wrap covering the top of the glass jar, prevents the movement of the vapor further away, such that the tiny condensed vapor gather together, to form big droplets under the plastic wrap that falls back into the jar, which is similar to the process of rainfall
The above processes are repeated as more water evaporates from the jar condenses on the plastic wrap and falls back into the jar, showing the process by which water is recycled from the lake into the atmosphere and back to the lake.
Explanation:
If you have a potential energy of 57 J. Now double your height, what is your new potential energy?
The new potential energy you will have, given that your height is doubled is 114 J
How do i determine the new potential energy?The following data were obtained from the question:
Initial potential energy (PE₁) = 57 JInitial height (h₁) = HNew height (h₂) = double of initial height = 2HNew potential energy (PE₂) =?The new potential energy can be obtained as illustrated below:
PE₁ / h₁ = PE₂ / h₂
57 / H = PE₂ / 2H
Cross multiply
57 × 2H = PE₂ × H
Divide both sides by H
PE₂ = (57 × 2H) / H
PE₂ = 57 × 2
PE₂ = 114 J
Thus, from the above calculation, we can conclude that the new potential energy is 114 J
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_______, ________, and ________ are renewable resources.
biomass energy, hydropower, and coal energy
hydropower, coal energy, and wind energy
biomass energy, hydropower, and wind energy
biomass energy, coal energy, and wind energy
✎help its an exam✎ ☕︎if any links I WILL REPORT☕︎
Answer:
biomass energy, hydropower and wind energy
What particle carries electric charge between your body and carpet when you experience static electricity?
Answer:
an electron.
Explanation:
When you walk on a carpet, some of the electrons from the atoms in the carpet are transferred to your body, giving you a negative charge. The electrons are then transferred back to the carpet when you touch a conductor, such as a doorknob, which can give you a shock due to the discharge of the static electricity.
4.
The "force" that moves electric charge carriers through an electric circuit is
a superconductor
resistance
An
10
a
MacBook Air
s
8
current
voltage
DII
8
A
EMA
4
F11
F12
Answer: Voltage
Explanation: Not really sure what all that other stuff is after your question...
The "force" that moves electric charge carriers through an electric circuit is ________.
An electric charge carrier moving through a circuit is a charged particle (usually electrons). The force that pushes it is called an electromagnetic force, commonly known as EMF.
Between atoms, EMFs are what attract electrons from one atom to another to form bonds. Likewise, In a circuit, the EMF is the driving force, which is known as voltage.
Superconductivity refers to a state in which these charge carriers travel at a specific voltage with no resistance, meaning no energy is lost. However, this isn't an independent force, so it's incorrect.
Resistance affects the circuit by slightly dampening the flow of charge carriers. Resistance commonly comes in the form of temperature or simply a characteristic of the material through which the circuit flows, so this is incorrect.
Current merely refers to the flow of charge carriers through a circuit in a given time window.
(Think of a circuit as a water pipe. Current is like the speed of a specific amount of water and Voltage (or EMF) is the pressure in the pipe. The higher the pressure, the faster the water flows. Resistance is anything in the pipe that impedes the water flow)
Two whistles emit sounds of wavelength 3.2 m and 2.9 m which produce a beat frequency of about? a) 2 hertz b) 3 hertz c) 4 hertz d) 7 hertz e) 11 hertz
Two whistles emitting sound of wavelength 3.2 m and 2.9 m would produce a beat of frequency 11 Hertz, hence option e.
The beat frequency (f_beat) is given by the difference in frequency (f) between the two whistles,
f_beat = |f₁ - f₂ |, frequencies of the two whistles are f₁ and f₂ . The frequencies can be calculated from the wavelengths (λ) using the formula,
f = c/λ, speed of sound in air is c, which is approximately 343 m/s at room temperature and atmospheric pressure. For the first whistle with a wavelength of 3.2 m,
f₁ = c/λ₁
= 343/3.2
= 107.1875 Hz
For the second whistle with a wavelength of 2.9 m,
f₂ = c/λ₂
= 343/2.9
= 118.2759 Hz
The difference in frequency is,
f_beat = |f_1 - f_2|
= |107.1875 - 118.2759| ≈ 11.1 Hz
Therefore, the beat frequency is approximately 11 hertz.
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Which definition describes a scientific theory?
OA. A claim, assumption, or method that is commonly thought to be
based on science but is not scientific
B. The pursuit of knowledge about the natural world and the
application of that knowledge
C. An explanation for a natural phenomenon that is based on facts
and is supported by the results of many experiments
D. A method of carefully examining an idea, using a variety of
thought processes to construct and evaluate knowledge
OA: A. A claim, assumption, or method that is commonly thought to be based on science but is not scientific.
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
A claim, assumption, or method that is commonly thought to be based on science but is not scientific is called pseudoscience. Pseudoscience is often presented as being scientific, but it does not meet the criteria of science. For example, pseudoscience may be based on speculation or personal opinion, rather than on evidence. It may also be based on experiments that are not properly controlled or that are not reproducible.
Pseudoscience can be harmful because it can lead people to make decisions that are not based on evidence. For example, people who believe in pseudoscience may be more likely to avoid proven medical treatments or to use unproven treatments that could actually be harmful.
It is important to be able to identify pseudoscience so that you can make informed decisions about your health and your life. If you are unsure whether something is pseudoscience, you can ask a scientist or do some research to find out more.
Why might earthquakes be much more intense closer to the initial disturbance than they are further away
A tourist, who weighs 705 N, is walking through the woods and crosses a small horizontal bridge. The bridge rests on two concrete supports, one at each end. He stops on the bridge. Assume that the board of the bridge has negligible weight. Where is he standing if the magnitude of the vertical force that a concrete support exerts on the bridge at the near end is 470 N?
а)one-fifth of the way along the bridge b)one-fourth of the way along the bridge c)one-third of the way along the bridge d)one-half of the way along the bridge f)one-sixth of the way along the bridge
The tourist is standing one-third of the way along the bridge (option c).
How to solveLet's denote the distance from the near end of the bridge to the point where the tourist is standing as x and the total length of the bridge as L.
According to the equilibrium condition, the sum of the forces exerted on the bridge is zero.
So, the vertical forces exerted by the two concrete supports should be equal to the weight of the tourist:
F_near + F_far = 705 N
Given that the magnitude of the vertical force exerted by the near end support is 470 N, we can calculate the force exerted by the far end support:
F_far = 705 N - 470 N = 235 N
Now, we can use the moment equilibrium condition, considering moments around the near end support:
Moment = Force × Distance
For the tourist:
Moment_tourist = 705 N × x
For the far end support:
Moment_far = 235 N × L
For equilibrium, the sum of the moments should be zero:
Moment_tourist - Moment_far = 0
Substituting the moments:
705 N × x - 235 N × L = 0
Now, we can solve for x/L, which represents the fraction of the way along the bridge where the tourist is standing:
x/L = (235 N × L) / 705 N
x/L = 235/705 = 47/141 ≈ 1/3
So, the tourist is standing one-third of the way along the bridge (option c).
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[Rotational motion] Calculate the length L between the 40N weight and the pivot needed to balance the beam shown in Figure 10.9. (solution says it's 7 m but it's unclear how it was obtained)
Answer:
L = 7m
Explanation:
The beam is balanced (not moving), so the moments about the pivot have to sum to 0.
Let x = dist. from pivot to the 10N ↓ force
CCW rotation is +
CW rotation is -
(100 N)(3 m) - (10 N)(x) - (40 N)(L) = 0
300 N·m - (10 N)(x) - (40 N)(L) = 0 divide by 10 on both sides
30 - x - 4L = 0
x + 4L = 30
10N is the Weight of the beam, so it is at the midpoint of the beam.
x = 5 - 3 = 2 m substitute into the equation above:
2 + 4L = 30
4L = 30 - 2 = 28
L = 28/4 = 7 m
convert 750W into kilowatts
Ans. 0.75
To convert watts into kilowatts we must divide it by 1000
so dividing 750W by 1000
we get,
750/1000 = 0.75
hence 750W in kilowatts equals to 0.75
5. An elephant has weight of 48000N and exerts pressure of 60000 Pa on the ground. What is the area of the elephant's feet in contact with the ground?
a. 1.25 m^2
b. 0.8 m^2
c. 2.0 m^2
d. 8.0 m^2
Answer:
A 1.25 m²
Explanation:
A 0.530-kg cart moving at 0.572 m/s to the right collides elastically with a 0.25-kg cart initially at rest. The 0.25-kg cart then moves off rapidly and compresses a spring before the 0.530-kg cart can catch it again.
To solve this problem, we can use the conservation of momentum and the conservation of kinetic energy.First, let's find the velocity of the 0.530-kg cart after the collision. We can use the conservation of momentum:m1v1 + m2v2 = m1v1' + m2v2'where m1 and v1 are the mass and velocity of the 0.530-kg cart before the collision, m2 and v2 are the mass and velocity of the 0.25-kg cart before the collision, and v1' and v2' are the velocities of the carts after the collision.Plugging in the numbers, we get:(0.530 kg)(0.572 m/s) + (0.25 kg)(0 m/s) = (0.530 kg)v1' + (0.25 kg)v2'Solving for v1', we get:v1' = [(0.530 kg)(0.572 m/s) + (0.25 kg)(0 m/s)] / (0.530 kg + 0.25 kg) = 0.378 m/s to the rightSo the 0.530-kg cart moves off to the right at 0.378 m/s after the collision.Next, let's find the maximum compression of the spring. We can use the conservation of kinetic energy:(1/2)m2v2^2 = (1/2)kx^2where k is the spring constant and x is the maximum compression of the spring.We know the mass and velocity of the 0.25-kg cart before the collision (v2 = 0 m/s), so we can solve for k:k = 2(1/2)m2v2^2 / x^2 = m2v2^2 / x^2Plugging in the numbers, we get:k = (0.25 kg)(0 m/s)^2 / x^2 = 0This means that the spring constant is 0, which is not physically possible. Therefore, there must be an error in the problem statement or some missing information that would allow us to calculate the maximum compression of the spring.
What is the S-P difference (sec)?
What is the amplitude (mm)?
What is the distance (km)?
What is the magnitude (M)?
Amplitude is the maximum vertical displacement of the seismic waves on the Seismogram. As evident from the graph, it is 60 mm.
What is the Time?1. Time at which P waves arrive- 0 sec
Time at which S waves arrive- 18 sec
S-P interval= Time at which S wave arrive- Time at which P wave arrive
S-P interval= 18-0= 18 sec
2. Amplitude is the maximum vertical displacement of the seismic waves on the Seismogram. As evident from the graph, it is 60 mm.
3. The distance is around 150 km and is evident on the Distance/S-P bar chart.
4. The magnitude is about 4 and can be found by joining S-P interval (18 sec) with the Amplitude i.e., 6 mm. The point of intersection of the line to the magnitude line gives the magnitude, i.e., 4.
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what are the two major types of mechanical energy and how do you calculate each equations with variables identified?
The equation to calculate both of them are:
KE = 1/2 * m * v^2
PE = m * g * h
What is Kinetic energy?Kinetic energy is described as the energy an object possesses due to its motion. The equation to calculate kinetic energy is:
KE = 1/2 * m * v^2
Where:
KE = Kinetic energy
m = Mass of the object
v = Velocity of the object
Potential energy is described as the energy an object possesses due to its position or configuration.
. The equation to calculate gravitational potential energy is:
PE = m * g * h
Where:
PE = Gravitational potential energy
m = Mass of the object
g = Acceleration due to gravity (9.81 m/s^2 on Earth)
h = Height or elevation of the object relative to a reference point
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Which of the following is the dimension of moment of inertia? (a) ML2 (b) MLT-1 (c) L2T 2 (d) L T-1
The dimension of the moment of inertia is [tex]ML^2[/tex]. Option A.
What is the moment of inertia?The moment of inertia represents the resistance of a body to rotational motion. It depends on the body's mass and the distribution of that mass around the axis of rotation.
The formula for the moment of inertia involves mass and distance and is expressed as:
I = mr^2
where
m is the mass of the bodyr is the distance from the axis of rotation.The dimension of mass is represented by M, and the dimension of distance is represented by L. Therefore, the dimension of moment of inertia is:
Moment of inertia = mass x distance^2 = M x L^2 = [tex]ML^2[/tex].
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