Final answer:
The conservation of momentum is the principle at play when Megan and Jason push off from one another. This is based on the fact that the momentum of a system remains constant in the absence of external forces, as well as demonstrating Newtons third law of equal and opposite reactions during their push-off.
Step-by-step explanation:
When two skaters, Megan and Jason, push off from one another, the most appropriate conservation law at play is conservation of momentum. According to this principle, if no external forces act on a system, the total momentum of the system before and after an event must be the same. This scenario also illustrates Newtons third law, which states that for every action, there is an equal and opposite reaction, meaning Megan and Jason push away from each other with equal force but in opposite directions, leading to the conservation of momentum.
In similar cases, such as an ice hockey puck striking a hockey stick lying flat on the ice, both linear momentum and angular momentum can be conserved if the puck and stick are considered an isolated system and are very resilient (elastic collision). In the absence of external forces, these quantities remain constant before and after the collision. However, the conservation of kinetic energy depends on the elasticity of the collision; it is conserved in perfectly elastic collisions but not in inelastic ones.
During a collision of two objects of equal mass, with one initially at rest and the other moving, provided no external forces act on them, momentum will be conserved. If object A stops completely and object B moves with the same speed as object A did originally, momentum is transferred but kinetic energy may not necessarily be conserved, indicative of an inelastic collision.