Mass of elevator is 1150kg and it’s counterweight is 1000kg. Tension in cord has same magnitude on both sides of pulley. What is the acceleration of the ELEVATOR? What is the tension in the cable?

A14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.