Item EG080002: When comparing two bike riders with different amounts of motion energy, the only way to know which one is riding faster is to also know the weight (mass) of each.

A girl and a boy are riding identical bicycles. The girl has more kinetic energy (motion energy) than the boy. Is the girl riding faster than, slower than, or at the same speed as the boy?

  1. The girl is riding faster than the boy.
  2. The girl is riding slower than the boy.
  3. The girl is riding at the same speed as the boy.
  4. The only way to know which child is riding faster is to also know the weight (mass) of each child.