A stone is dropped from height h. Arrive at an expression for the time taken to reach the ground.

a)Identify the scalar quantity from the following alternatives. (i)Momentum,(ii)work,(iii)Torque,(iv)Acceleration. b)A man throws a stone up into air at an angle theta with the horizontal.Draw the path of the projectile and mark directions of velocity and acceleration at the highest position. c)Derive an expression for the maximum height reached by the stone.

A ball at rest is dropped from a height of 12m . It loses 25% of its kinetic energy on striking the ground. Find the height to which it bounces.