Physics linear momentum/ average force

[astru025]

Homework Statement

A very hard rubber ball (m = 0.2 kg) is falling vertically at 3 m/s just before it bounces on the floor. The ball rebounds back at essentially the same speed. If the collision with the floor lasts 0.05 s, what is the average force exerted by the floor on the ball?

Homework Equations

Net force= change in momentum/ time taken
Linear momentum= mass x velocity

The Attempt at a Solution

I found the linear momentum of the ball before it hits the ground: .2 kg x 3 m/s= .6
After this I am lost and am not sure what I do next. I not sure what I need to do in order to find average force from this information.

 

[Abhilash H N]

Now you have the initial momentum find the final momentum... Then apply the formula for average force...

 

[haruspex]

... Bearing in mind that momentum is a vector, so if you are measuring momentum as positive downwards then after the bounce it will be negative.