Find the speed at which Superman (mass=89.0 kg) must fly into a train (mass = 19564 kg) traveling at 65.0 km/hr to stop it.
The system (train + Superman) must end up with zero momentum. With no external forces, Superman's initial momentum must be equal and oppositely directed to the train's. (This is not good for the passengers, as they stop too quickly.)
Running into the train at that speed would severely damage both train and passengers. Calculate the minimum time Superman must take to stop the train, if the passengers experience an average horizontal force of 0.520 their own weight.
How far does the train then travel while being slowed to a stop?
1 answer
That is right. So what is the question?