A100-kg moving at 15 m/s collides with a 50-kg cart at rest causing both cars to move together in the same direction. if momentum is conserved, at what speed are the two carts now moving?

30m/s

Explanation:

100 / 50 = 2 * 15 = 30m/s

Explanation:

Data:

Cart 1: m₁ = 100 kg; v  =15 m/s

Cart 2: m₂ =  50 kg; v₂ = ?

Calculations:

I assume that the two carts are going at the same speed v₂ after the collision.

it is the most commonly accepted one