What is mechanical energy? Give two examples where a body can be said to have it.

Mechanical energy is the sum of kinetic and potential energy; a body has it when it is moving or when it is raised/stretched/compressed. Examples: a moving car (kinetic) and a stretched bow (elastic potential).

• Moving car: energy of motion lets it do work (push air, climb hills).
• Stretched bow or compressed spring: stored energy can launch an arrow or move an object when released.
• Falling stone: at height it has gravitational potential; during fall it converts to kinetic.