Question

5. A moving car has kinetic energy. If the mass is doubled what happens to the

amount of kinetic energy? If the speed is doubled what happens to the amount
of kinetic energy?

Answer 1

See below ~

Explanation:

Change in KE if mass is doubled

• KE (original) = 1/2mv²
• KE (new) = 1/2 x (2m) x v²
• KE (new) = mv²
• ⇒ KE is doubled

Change in KE if speed is doubled

• KE (new) = 1/2 x m x (2v)²
• KE (new) = 1/2 x 4 x mv²
• KE (new) = 2mv²
• ⇒ KE is quadrupled