A subway accelerate gradually (a= 1.2 m/s/s) from rest at one station until it is halfway to the next station and then decelerates gradually (a=-1.2 m/s/s) for the final half of the trip until it comes to rest. The two stations 1100 m apart.

Question

A subway accelerate gradually (a= 1.2 m/s/s) from rest at one station until it is halfway to the next station and then decelerates gradually (a=-1.2 m/s/s) for the final half of the trip until it comes to rest. The two stations 1100 m apart. 
A) what is the maximum speed the train reaches?
B) how long does it take to travel between the stations?

Damon · Answer

1100.2 = 550 550 = (1/2) a t^2 550 = .5 * 1.2 * t^2 t = 30.3 seconds to go halfway (same for the second half) v = a t = 1.2 * 30.3 = 36.3 m/s 2 t = 60.6 seconds