Q1. Dan is gliding on his skateboard at 4 m/s. He suddenly jumps backward off the skateboard, kicking the skateboard forward at 6 m/s (as measured by an observer on the ground). Dan's mass is 50 kg and the skateboard's mass is 7 kg. How fast is Dan going as his feet hit the ground?

Q2. A block of mass 2.20 kg is accelerated across a rough surface by a light cord passing over a small pulley. The tension T in the cord is maintained at 10.0 N, and the pulley is .100m above the top of the block. The coefficient of kinetic friction is .400. a) find out the acceleration of the block when x=.400m b) explain the general behaviour of the acceleration as the block slides from a location where x is large to x=0. c) Find a maximum value of the acceleration and the position x for which it occurs. d) Find a value of x for which acceleration is zero.