A car, initially still, accelerates up to a maximum speed of v, and then slows down to a stop again. The plot of the velocity over the time (t seconds from start to stop) is a semicircle. (i'm sorry i cannot post the diagram, but try to imagine it, it is a simple semicircle where the topmost point is the max. veloicity and t is the total time elapsed.) Now as all mathematicians know, it is often useful to find the area under the curve, in this case to find how far the car has travelled. One mathematician claims that since the radius of the semicircle is v, the distance travelled is (pi/2)*v^2. Another disagrees, saying that t is the diameter of the semicircle, so the distance is actually (pi/2)*(t/2)^2. Which one is right? if you know the answer, do not spoil it for others, to check if u r correct or not, send me a PM.