A ball is dropped from a height of 1.20 m and hits the floor. The ball compresses and then reforms to spring upwards from the floor to a height of 0.86 m. The time from the ball's first contact to when it left contact with the floor was 0.091 s. Calculate the ball's acceleration while it is in contact with the floor.

Explanation:

The formula for the velocity of the ball is

1. Velocity at time of impact

2. Velocity on rebound

The ball has enough upward velocity to reach a height of 0.86 m.

3. Acceleration

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.