Answer:
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