An ice skater at rest pushes against a sled at rest, causing both the skater and sled to move away from each other with different acceleration. This is an example best described by

Newton's third law of motion.

Explanation:

An ice skater at rest pushes against a sled at rest, causing both the skater and sled to move away from each other with different acceleration. It is based on Newton's third law of motion.

Third law says that, for every action there is an equal; and opposite reaction. Here, action is force applied by ice skater and reaction is motion of skater and sled away from each other with different acceleration.