Dropped Tennis Ball - HELP PHYSICS?

Question

A 0.8 kg tennis ball is dropped from rest at a height of 5.6 m onto a hard floor.

a) What is the speed of the ball at the instant of contact with the floor?

|v| = m/s
A flash photograph shows that the ball is compressed a maximum of 0.6 cm when it strikes the floor. b) Assuming that the acceleration of the ball is constant during its contact with the floor, what force does the floor exert on the ball?

|f| = N
c) Over what time does the force act in bringing the ball to rest?

D t = s

Answer 1

Hmmm... a tennis ball weighing 0.8kg. This a cannon ball!

a) V=gt
t= sqrt(2h/g)
V=gsqrt(2h/g)
V=sqrt(2hg)

Or using energy relationship Pe=Ke
mgh=(1/2) m V^2
V=sqrt( 2 g h) [confirmed]
b)
x=(1/2)at^2
a=2 x /(t^2)
v=at
t=V/a

a=2x/(V/a)^2
a=2xa^2/V^2
a=V^2/(2 x)

F=ma=mV^2/(2 x)


c) t=V/a = V/(V^2/(2 x))
t=2x/V