Work Energy Theorem

A body of mass kg is thrown upwards with a velocity ms^-1. It momentarily comes to rest after attaining a height of m. How much energy is lost due to air friction?
(Take ms^-2)
1. J
2. J
3. J
4. J

Consider a drop of rainwater having a mass of falling from a height of It hits the ground with a speed of Take as constant with a value The work done by the
(i) gravitational force and the (ii) resistive force of air is:

1.
2.
3.
4.

A bullet from a gun is fired on a rectangular wooden block with velocity . When bullet travels cm through the block along its length horizontally, velocity of bullet becomes . Then it further penetrates into the block in the same direction before coming to rest exactly at the other end of the block. The total length of the block is:

1.	cm	2.	cm
3.	cm	4.	cm

The kinetic energies of two similar cars and are and respectively. On applying brakes, car stops after and car stops after If and are the forces applied by the brakes on cars and respectively, then the ratio is:

1.		2.
3.		4.