A 60 ton railcar and its cargo, a 27 ton trailer, are moving to the right at 4 mph when th...

A 60 ton railcar and its cargo, a 27 ton trailer, are moving to the right at 4 mph when they come into contact with a bumper that is able to bring the system to a stop in 0.78 s. Determine the magnitude of the average force exerted on the railcar by the bumper.

Figure P5.9