The kinetic energy of a car travelling at 10 m/s is four times
the kinetic energy of a
travelling at 5 ms/s.
car
Why is this so?

Explanation:

Consider the KE formula.

KE = 1/2 m v^2

If you double the speed, it get's squared. m should stay the same.

suppose m = 10 and v = 5

KE = 1/2 * 10 * 5^2

KE = 1/2 * 10 * 25

KE = 5 * 25

KE = 125

Now don't change the m and make v = 10

KE = 1/2 * 10 * 10^2

KE = 5 * 10^2

KE = 5 * 100

KE = 500

If you multiply 4 * 125 you get 500

D o notice that doubling the speed increases the KE by 4?