Well, a is correct but how can b be correct then? If the initial speed (at t = 0) is 60m/s, then the car can't be at rest at t = 0. The car is at rest when v = 0, take it from there.Originally Posted by tnkfub
For c, when v is positive: the car moves forward (and backward when v < 0).
Draw the diagram yourself, it'll help for e as well, f seems to be ok.