Question

A 2.00-kg object traveling east at 20.0 m/s collides with a 3.00-kg object traveling west at 10.0 m/s. After the collision, the 2.00-kg object has a velocity 5.00 m/s to the west. How much kinetic energy was lost during the collision?

Answer 1

Lost K.E.= Final K.E. - Initial K.E.
ΔK.E. = 1/2 mv₁² - 1/2 mv₂²
ΔK.E = 1/2 m [v₁²-v₂²]
ΔK.E = 1/2 * 2 * [20-5]
ΔK.E = 1 * 15
ΔK.E = 15 Joules

So, your final answer is 15 Joules.

Answer 2

I think u hv to use conservation of momentum formula