Answer
The correct answer is: (c) increases by a factor of 9
Work Step by Step
We can find an expression for the kinetic energy when the car is moving at a speed of $3v$:
$KE = \frac{1}{2}m(3v)^2 = 9\times \frac{1}{2}mv^2$
The correct answer is: (c) increases by a factor of 9
