posted by Matthew .
Jennifer (mass 58.0 kg) is standing at the left end of a 13.0 m long 594.0 kg cart that has frictionless wheels and rolls on a frictionless track. Initially both Jennifer and the cart are at rest. Suddenly, Jennifer starts running along the cart at a speed of 5.70 m/s relative to the cart. How far will Jennifer have run relative to the ground when she reaches the right end of the cart?
In this situation, the center of mass of Jennifer and the cart (considered together) will remain in the same place.
The speed that she runs won't affect her position relative the the ground. It will only affect how soon she gets there.
Those hints should guide you easily to the solution.