A moving car has kinetic energy. If it speeds up until it is going four times faster than before, how much kinetic energy does it have in comparison?

Ratio of final kinetic energy to initial kinetic energy is 16.

Explanation:

Kinetic energy, KE = 0.5mv²

Here car speeds up to four times the initial speed, we need to find ratio of final kinetic energy to initial kinetic energy.

Final speed = 4 x Initial speed = 4v

Initial KE = 0.5mv²

Final KE = 0.5 x m x (4v) ²

Final KE = 16 x 0.5 x m x v²

Final KE = 16 x Initial KE

Ratio of final kinetic energy to initial kinetic energy is 16.