The velocity of a train is given by v = 250 −1/2t^2 .

(a) What is the displacement of thetrain after 5 hours? and 10 hours?

I integrated and got the correct answers for both being

d5 =7375 /6,

d10 =7000 /3

(b) At what times is the displacement of the train zero?

I made 250-1/2t^2 = 0 to find the displacement of the train at 0 but I couldn't work it out...hmm

maybe my thinking is messed up.

(c) Describe what’s happening to the train.

hmmmm....

Thomas the tank engine...