1. A spacecraft that is initially at rest turns on its engine at t = 0. If its mass is m = 3000 kg and the force from the engine is 45 N, what is the acceleration of the spacecraft?
2. A hockey puck moves on an icy surface that is frictionless, with a constant speed of 30 m/s. How long does it take the puck to travel the length of the hockey rink (60 m)?