A sphere is released into the atmosphere where air resistance is present. As it falls it loses 7J of potential energy. How much kinetic energy did it gain?

7 J

Explanation:

Given that,

A sphere is released into the atmosphere where air resistance is present.

The lose in energy is equal to 7 J

We need to find the gain in its kinetic energy.

We know that, as per the law of conservation of energy,

Loss in potential energy = gain in kinetic energy

⇒

Gain in kinetic energy = 7 J

Hence, the gain in kinetic energy is 7 J.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards