How to calculate average force?

[kings13]

Homework Statement

A .140 kg baseball traveling 35 m/s strikes the catchers mitt, which, in bringing the ball to rest, recoils backward 11 cm. what was the average force applied by the ball on the glove?

Homework Equations

The Attempt at a Solution

ughh i have really no idea. i missed the lecture day for force and have no idea how to begin. i drew a picture but don't understand any of the equations regarding force

 

[ashishsinghal]

when considering average force you assume the force is constant.
if that is so then finding the work done would be easy. now just use work energy theorem