How does the law of conservation of momentum apply to skateboarders pushing off each other?

The law of conservation of momentum states that in a closed system, if no external forces act on the objects within that system, the total momentum before any interaction must be equal to the total momentum after the interaction. In the context of skateboarders pushing off each other, when one skateboarder pushes against the other, they exert equal and opposite forces on each other.

Before the push, both skateboarders have a certain amount of momentum based on their velocities and masses. When they push off from one another, they exert forces that change their individual momenta, but the total momentum of the system (both skateboarders together) remains unchanged. The momentum lost by one skateboarder is gained by the other, ensuring that the total remains constant.

This principle emphasizes that in the absence of external influences, such as friction or other forces, the momentum before the push (the sum of the individual momenta of both skateboarders) equals the momentum after the push (the new individual momenta).