Question

Two bullets with the same mass are fired at speeds of 30 m/s and 60 m/s respectively. What is the ratio of KE between the two shots? Find both KE’s.

Answer 1

The ratio of KE is 1:4

Step-by-step explanation:

When doubling the velocity off the objects (assuming that the mass is the same which is given), the kinetic energy of the bullet at double the speed is 4 times greater than the initial, so the ratio is 1:4.

You can work out this answer with an example where mass is 100g

KE = 1/2mv^2

KE = 1/2(100)(30)^2

KE = 45000J

doubled:

KE = 1/2mv^2

KE = 1/2(100)(60)^2

KE = 180000J

180000J/45000J = 4