Question

A student throws a .1kg ball at a wall. The ball hits the wall perpendicularly with a speed of 5m/s & then bounces back w/ a new speed of 4m/s. What impulse is given to the ball by the wall?

I used deltaP= m deltaV so deltaP= .1*(-1) to get -.1N-s.

I got it wrong! Can someone tell me why?

Thank you :)

Answer 1

the change in velocity (delta v) is
... 9 m/s

5 m/s in one direction, then 4 m/s in the opposite direction

Answer 2

Oh... So essentially I'm saying 5-(-4) which is 5+4? that makes sense... Thank you :)