Amass m is hanging from a rope of length l and mass m. a student gives the mass a quick horizontal shake to set up a wave which travels along the rope. give an expression, in terms of the provided variables, for the speed of the wave at the bottom of the string. you may assume the mass of the rope m is much less than m

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?