Calculating Acceleration from High Speed Camera Footage

[gr3g1]

I have a question in my serway physics book..
The question goes like this:

A 50g ball traveling at 25m/s bounces off a brick wall and rebounds at 22m/s. A high speed camera records this event. If the ball is in contact with the wall for 3.5ms what is te magnintue of te average acceleration of te ball durning this time interval..

I tried using delta v over delta t to find the answer, but the answer is suppose to be : 1.34*10^4

Thanks

 

[Galileo]

I tried using delta v over delta t to find the answer, but the answer is suppose to be : 1.34*10^4
Thanks

The approach is correct and the answer it gives is indeed 13.4*10^3 m/s^2

 

[gr3g1]

Ok , the orignal v is 25, and the final v is 22.
The time is just .0035

-3/.0035 ?

 

[Tide]

Where did the "3" come from?

 

[gr3g1]

the change is 3 m/s

 

[gr3g1]

Wait, Nevermind, I got it