posted by patt .
A 5.11-kg pendulum bob, at a height of 0.730 m above the floor, is released and swings down to the ground where it collides elastically with a 2.29 kg block initially at rest. The block then slides up a 31.0° incline. Find how high up the incline the block will slide if
(a) the plane is frictionless
(b) the plane is rough with a coefficient of friction 0.429
The answer for the part a is saying its 1.39 m, but I can't figure out the part b.