A train starts from rest and accelerates uniformly until it has traveled 2.1 km and acquired a forward velocity of The train then moves at a constant velocity of for 400 s. The train then slows down uniformly at until it is brought to a halt. The distance traveled by the train while slowing down is closest to:

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?