Physics 12
posted by solexgirl12 on .
This came up on our test review for tomorrow, and I'm stumped!
"A hockey puck of mass 0.51 kg is moving north across the ice with a speed of 32 m/s. If it is hit with a hockey stick so as to make it travel due west at the same speed, what is the magnitude of the impulse delivered to the puck?"
My FBD shows the puck bouncing off the stick and heading in a unknown direction at 32 m/s. I found the momentum of the puck to be p=16.32, but I can't seem to calculate the magnitude. Can anyone help me?

There is a change in direction of the momentum by 90 degrees. The magnitude of the momentum remains 16.32 kg m/s.
The magnitude of the impulse equals the magnitude of the momentum change VECTOR. That would be sqrt2 times 16.32 kg m/s
Do you see why? If not, draw yourself the vector diagram 
Thanks! I had to go through the whole vector diagram, but got it in the end.