A cart with no load is travelling along a level track at a steady velocity. The resistive forces on the cart are negligible. A heavy rock is dropped straight down into the cart. The cart then keeps moving horizontally with the rock inside it. How do the momentum and kinetic energy of the cart with the rock inside compare with the momentum and kinetic energy of the empty cart?
- AThe cart with the rock inside has a smaller momentum and a smaller kinetic energy.
- BThe cart with the rock inside has a smaller momentum and the same kinetic energy.
- CThe cart with the rock inside has the same momentum and a smaller kinetic energy.
- DThe cart with the rock inside has the same momentum and the same kinetic energy.