Average force applied by baseball on glove

[balletgirl]

Homework Statement

A 0.140-kg baseball traveling 45.0 m/s strikes the catcher's mitt, which, in bringing the ball to rest, recoils backward 11.0 cm. What was the average force applied by the ball on the glove?

Homework Equations

F=ma ?

The Attempt at a Solution

It is the whole "backward 11.0 cm" part that confuses me.

 

[JDHalfrack]

Clearly, the question is how can you find acceleration?

Hint: if the ball is initially traveling at 45 m/s, and the ball comes to rest after 11 cm, what equation can you use to find acceleration?

 

[balletgirl]

Okay, so I used the equation vf^2=vi^2-2ad.
0= 45^2 - 2*a*.11m
I ended up with 9205 m/s/s as the acceleration.

After plugging it into F=ma, I got 1,289N as the force. It seems too high.
Thanks by the way.

 

[JDHalfrack]

I got 1,289N as the force. It seems too high.

Excellent. That's what I got too. And, think about it. A baseball traveling 45 m/s comes to rest in only 11 cm! It takes a tremendous amount of force to stop it!