A 6kg bowling ball is traveling at 10 m/s is brought to rest after colliding with a wallin a collision that lasts .1s.
What is the impulse experienced by the ball?

I calculated that it was -60kgm/s but that is incorrect. Help?

Hmmmm... it certainly seems like a pretty straightforward question.

Impulse = change in momentum = 0 - 6*10 = -60 kg*m/s.

Your answer certainly looks correct to me.

Do you know what the supposedly "correct" answer is? It could be something stupid like "60 kgm/s backwards", which is exactly the same thing as what you got, of course.