A child's toy train involves an engine of mass 5.00 kg and 5 toy freight cars mass of 1.0 kg each. For simplicity treat the wheels of the freight cars as frictionless so that all traction is provided by the locomotive which can generate a force of 20 N. What is the tension in the coupling between the locomotive and the first car?

Suppose the track has a 10 degree downgrade. What acceleration will the train have going uphill? (Assume the locomotive continues to generate the same force in its forward direction)