Question

Suppose the collision speed is 20 mph and the rebound speed is 5 mph. The energy ratio is?

Answer 1

Answer:

The energy ratio is $16:1.$

Explanation:

The kinetic energy of the 20mph object is

$K_1 = \dfrac{1}{2}m(20mph)^2$,

and the kinetic of the same abject at 5mph is

$K_2 = \dfrac{1}{2}m(5mph)^2;$

therefore, the ratio of $K_1$ to $K_2$ is

$\frac{K_1}{K_2} = \frac{\dfrac{1}{2}m(20mph)^2}{ \dfrac{1}{2}m(5mph)^2} = \frac{(20mph)^2}{(5mph)^2} =\frac{16}{1}$

Thus, the energy ratio is $K_1:K_2 = 16:1$.