Question

An express subway train passes through an underground station. It enters at t = 0 with an initial velocity of 23.0 m/s and decelerates at a rate of 0.150 m/s2 as it goes through. The station in 210 m long.
(a) How long is the nose of the train in the station?

(b) How fast is it going when the nose leaves the station?

(c) If the train is 130 m long, at what time t does the end of the train leave the station?

(d) What is the velocity of the end of the train as it leaves?

Additional Materials

Answer 1

(a) use d=vi*t+0.5*a*t^2
manipulate the equation to solve for t

210 m = (23 m/s)t+0.5(0.150 m/s^2)*t^2
t = 9.41 s

(b) v = d/t
= 210 m/ 9.41 s
= 22.3 m/s

I'm still trying to figure out the rest...

Answer 2

3.60