posted by Nick .
A 0.028 kg rifle bullet traveling 210 m/s buries itself in a 3.1 kg pendulum hanging on a 2.5 m long string, which makes the pendulum swing upward in an arc.
1. Determine the vertical and horizontal components of the pendulum's displacement.
Use conservation of momentum to find the initial velocity of the block/bullet.
Now using that velocity, find its intial KE. If you set that KE = mgh, h is the max vertical height.
Now draw the figure, find out at h what the angle the pendulum is, and from that, the horizontal movement.