Physics
posted by Tracy on .
A simple pendulum 1.50 m in length has a 500g putty ball as an end bob. The pendulum is pulled aside 60° from the vertical and given an initial tangential speed of 1.20 m/s. At the bottom of the arc path, the bob hits and sticks to a 200g putty ball sitting on a tee. (a) Determine the speed of the 500g ball just before it hits the 200g ball and the speed of the combined masses right after they stick together. (b) How much mechanical energy is lost in the collision? (c) What is the maximum angle to which the combined balls swing on the other side?

find the initial height of the bob from the angle and the length.
Then, find total initial energy (KE+GPE)
at the bottom of the swing, all that energy is KE, find the velocity.
Then, at the bottom, use conservation of momentum to find combined velocity.
At That point, you need to caculate energies. 
i did that for part a but i got 2.73 and the answer says its 2.87

wait nevermind i got it. i put in the wrong number. thanks :D