A 130g ball moving at 0.35m/s in the x-direction is subject to a 0.25N force in the - y-direction for 1.0s. Find the magnitude of the ball's momentum change.
The momentum in the x direction remains
0.130*0.35 = 0.0455 kg m/s
The momentum in the y direction goes from zero to
0.25*1 = 0.25 kg m/s
Add those two components vectorially for the final momentum magnitude. I get 0.2541 kg m/s
Subtract the initial momentum magnitude from that