# Homework Help: Speed & Direction of Motion

1. Apr 28, 2013

### Legerity

1. The problem statement, all variables and given/known data

To protect their young in the nest, peregrine falcons will fly into birds of prey (such as ravens) at high speed. In one such episode, a 600g falcon flying at 20.0m/s hit a 1.40kg raven flying at 8.0m/s. The falcon hit the raven at right angles to its original path and bounced back at 5.0m/s. By what angle did the falcon change the raven's direction of motion? What was the raven's speed right after the collision?

2. Relevant equations
ΔP, arctan(P_y/P_x)

3. The attempt at a solution
I tried to find each individual momentum vector for the raven and falcon, then did arctan(P_fal/P_rav) to get the direction of the motion, but my answer of 47° turned out to be incorrect. Could someone please guide me on how to work out both of these problems?

2. Apr 28, 2013

### UVW

Remember, the momentum of the falcon is not going to come into play when finding the direction of motion of the raven. Why don't we find the x and y components of the raven's final momentum and go from there?

3. Apr 28, 2013

### haruspex

That doesn't compute the direction of anything interesting as far as I can see.