A sports car traveling along a straight line increases it speed from 20 mi/h to 60 mi/h. (a) what is the ratio of the final to the initial magnitude of its momentum? (b)What is the ratio of the final to the initial kinetic energy?

I have figured out (a) and it is 3. I am lost on (b).
Thank you in advance!

Question

A sports car traveling along a straight line increases it speed from 20 mi/h to 60 mi/h. (a) what is the ratio of the final to the initial magnitude of its momentum? (b)What is the ratio of the final to the initial kinetic energy?

I have figured out (a) and it is 3. I am lost on (b).
Thank you in advance!

anonymous · Answer

Kinetic energy varies with the square of the speed. Tripling the speed of the object causes the kinetic energy to increase by a factor of 9.

anonymous · Answer

Than you very much! I appreciate it.