Answer:
The energy ratio is [tex]16:1.[/tex]
Explanation:
The kinetic energy of the 20mph object is
[tex]K_1 = \dfrac{1}{2}m(20mph)^2[/tex],
and the kinetic of the same abject at 5mph is
[tex]K_2 = \dfrac{1}{2}m(5mph)^2;[/tex]
therefore, the ratio of [tex]K_1[/tex] to [tex]K_2[/tex] is
[tex]$\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} $[/tex]
Thus, the energy ratio is [tex]K_1:K_2 = 16:1[/tex].
