Answer:
<em>d. The sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
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Explanation:
Let us take the momentum of a photon unit as u
we know that the rate of change of momentum is proportional to the force exerted.
For a absorbing surface, the photon is absorbed, therefore the final momentum is zero. From this we can say that
F = (u - 0)/t = u/t
for a unit time, the force is proportional to the momentum of the wave due to its energy density. Therefore,
F = u
For a reflecting surface, the momentum of the wave strikes the sail and changes direction. Since we know that the speed of light does not change, then the force is proportional to
F = (u - (-u))/t = 2u/t
just as the we did above, it becomes
F = 2u.
From this we can see that the force for a reflective sail is twice of that for an absorbing sail, and we know that the pressure is proportional to the force for a given area. From these, we conclude that <em>the sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.</em>
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Jemima is running with a velocity of 5m/s. She has a mass of 65kg, what is her kinetic energy would be 812.5 Joules.
<h3>What is mechanical energy?</h3>
Mechanical energy is the combination of all the energy in motion represented by total kinetic energy and the total stored energy in the system which is represented by total potential energy.
As given in the problem we have to calculate the Kinetic energy of the Jemima,
Kinetic energy = 1/2 ×mass×velocity²
=0.5×65×5²
=812.5 Joules
Thus, the kinetic energy of the Jemima would be 812.5 Joules.
To learn more about mechanical energy, refer to the link;
brainly.com/question/12319302
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Force = (mass) · (acceleration)
= (15 kg) · (8 m/s²)
= 120 kg-m/s² = 120 newtons
Answer: D
Explanation:
Frank’s Furniture trains all of its employees to use computers is an example of an improvement in human capital.
Answer:
As the warmer air over the equator rises, colder air from the poles rushes toward the equator to take its place. Global winds push air masses around Earth and bring changes in the weather. In the United States, global winds called the prevailing westerlies push air masses from west to east.
Explanation:
