Item EG081006: Two objects that are moving at the same speed must have different masses in order to have different amounts of motion energy.

Two objects are moving at the same speed. The objects have different amounts of kinetic energy (motion energy). Which of the following must be true?

  1. The objects are different sizes.
  2. The objects have different masses.
  3. The objects are made of different materials.
  4. The objects are moving in different directions.