How Does a Pellet Gun's Force Affect a Wall?

[WarpDrive]

I am having trouble understanding another of my homework problems.

A Pellet gun fires ten 2.14 grams pellets per second with a speed of 483 m/s. The pellets are stopped by a rigid wall. a) find the momentum of each pellet. b) Calculate the average force exerted by the stream of pellets on the wall. c) if each pellet is in contact with the wall for 1.25ms, what is the average force exerted on th ewall by each pellet while in contact? Why is this so different from b?

I got the answers to a and c, but I don't understand b. My teacher mentioned something about integrating something, but I don't understand what. I know that J = Favg*deltaT and J = integral(F dt), but how do I use that to find Favg? He said you get an answer of something per second, because of the integral, but I'm just getting more and more confused about it.

Thanks!

 

[Doc Al]

You realize that $$J = F_{ave} \Delta t$$, but what else does impulse equal? Answer/hint: The change in momentum.