Question

If they are traveling at the same speed, which will have the most kinetic energy?

Answer 1

Answer: B. (A 25 kg ball)

Explanation:

Since $KE = \frac{1}{2} mv^{2}$, and velocity is the same for all four balls, the ball with the greatest mass will have the greatest kinetic energy (since mass and KE are directly related). Below shows these calculations:

A. m = 5

$KE = \frac{1}{2} mv^{2}$

$KE = \frac{1}{2} (5)v^{2}$

$KE = 2.5v^{2}$

B. m = 25

$KE = \frac{1}{2} mv^{2}$

$KE = \frac{1}{2} (25)v^{2}$

$KE = 12.5v^{2}$

C. m = 10

$KE = \frac{1}{2} mv^{2}$

$KE = \frac{1}{2} (10)v^{2}$

$KE = 5v^{2}$

D. m = 1

$KE = \frac{1}{2} mv^{2}$

$KE = \frac{1}{2} (1)v^{2}$

$KE = 0.5v^{2}$