(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A ball of mass 200 g is released from rest at a height of 2.00 m above the floor and it rebounds straight up to a height of 0.900 m. (a) Determine the ball's change in momentum due to its contact with the floor. (b) If the contact time with the floor was 0.0950 seconds, what was the average force the floor exerted on the ball, and in what direction?

2. Relevant equations

Δp=m(v-v_{o})

F_{avg}=Δp/Δt

w=mg

3. The attempt at a solution

The answer to a) is 2.09 kg x m/s, and the answer to b) is 24.0 N upward.

I understood everything except for a portion of b. I used F_{avg}=Δp/Δt=2.09 kg x m/s/.0950s to calculate 22.0 N, but you're supposed to add weight to that as well. That is where I get stuck. I don't understand why you're supposed to add w=(.200kg)(9.8 m/s) to the 22 N.

Can someone draw a picture of this and also explain why you add g/why it's upward?

My book says "The floor also needs to support the weight of the ball during impact."

I just don't get that

Thanks so much!

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Average force the floor exerted on the ball

**Physics Forums | Science Articles, Homework Help, Discussion**