Under which condition is no work done? a force pushes an object and slows it down. a force pulls an object and speeds it up. a force pulls down on an object that moves downward. a force pushes up on an object that stays in place.

The correct answer is when a force pushes up on an object that stays in place under this condition no work is done.

Explanation:

A force is said to do work when there is a displacement of the object.

In the first given condition, a force pushes an object and slows it down. In this case, the work is done by the frictional force. There is a displacement of the object when the object slows it down.

In the second given condition, a force pulls an object and speeds it up. In this case, force is applied and the object start accelerated. There is a displacement when it speeds up.

In the third given condition, a force pulls down on an object that moves downward. Here, the work is done by the gravity. There is a displacement of the object when it moves downward.

In the fourth given condition, a force pushes up on an object that stays in place. As there is no displacement. No work is done in this case.

Therefore, the correct answer is when a force pushes up on an object that stays in place under this condition no work is done.

specific latent heat of fusion, lf, of a substance is defined as the amount of heat required to change a unit mass of the substance from solid to liquid state, without any change in the temperature.

explanation:

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)