while a small laboratory cart is moving over a table at constant velocity, a lucky mass is gently deposited on it. Assuming that the mass had zero momentum to begin with, what happens to the velocity of the cart? 2. The diagram below shows a compressed spring between two carts initially at rest on a horizontal frictionless surface. After the string is cut, cart B moves to the right at a speed of 15 m/s. What must the speed and direction of cart A be after the string is cut? A B 2 kg 1 kg 3. A 1500-kg cart moving at a speed of 8.0 m/'s collides with a 4500-kg cart at rest as shown in the following diagram. After they collide the two carts interlock and move together. Calculate the speed of the combined carts after the collision. VI = 8.0 m/s 1500-kg 4500-kg