Linear Collision & Impulse_2

As shown in the figure below, a rubber ball with mass m equal to 50 g is dropped from a height of
hi = 1.8 m . It collides with a table, then bounces up to a height of hf =1.2 m . The duration of the collision (the time during which the rubber ball is in contact with the table) is tc = 25 ms. Neglect air resistance.
(D) Find the magnitude of the average contact force that the table exerts on the ball.(E) Find the change in the kinetic energy of the ball during the collision.