Help, about repulsive force

[tongtong1993]

Homework Statement

A ball of 2kg drops from rest to ground from a height 5m and rebounds to the same height.
If the time of duration of the impact between the ball and the ground is 0.2s
what is the total reaction of the ground on the ball

Homework Equations

The Attempt at a Solution

mgh=0.5mv^2
2(10)(5)=1.5(2)v^2
v=10
F=ma
F=2(10/0.2)
F=100

 

[ehild]

What is the change of velocity of the ball during the impact?

ehild

 

[tongtong1993]

20ms^-1??

 

[ehild]

Yes, this is the magnitude of the velocity change during 0.2 s.

ehild