What is the average force on the wall?

[zade70]

Homework Statement

A ball hits the wall in a normal direction with v=10m/s. After the hit which lasted 0.2 Seconds, it turned in the same direction with v=10m/S. Knowing that its mass is 0.5 kg, find the average force that hit the wall.

Homework Equations

F=m*a, a= (v-v₀)/t

The Attempt at a Solution

a=(0-10)/0.2=-50m/S₂, F= 50*0.5= 25N, but the answer is 50N

 

[billy_joule]

What is the final velocity minus the initial velocity? Your calculation assumes the final is zero...