Question

When the speed of your car is doubled, by what factor does its kinetic energy increase?

a. 4
b. √2
c. 8
d. 2

Answer 1

a. 4

Step-by-step explanation:

Hi there!

The equation of kinetic energy (KE) is the following:

KE = 1/2 · m · v²

Where:

m = mass of the car.

v = speed of the car.

Let´s see how would be the equation if the velocity is doubled (2 · v)

KE2 = 1/2 · m · (2 · v)²

Distributing the exponent:

KE2 = 1/2 · m · 2² · v²

KE2 = 1/2 · m · 4 · v²

KE2 = 4 (1/2 · m · v²)

KE2 = 4KE

Doubling the velocity increased the kinetic energy by 4.