Question

A car is driven on a straight track such that its displacement from the starting point is given as x = t + 2t2. What is the average velocity (average rate of change of displacement) of the car between t = 2s and t = 4s?

Answer 1

Average velocity = (x(4) - x(2))/(4 - 2) = ((4 + 2(4)^2) - (2 + 2(2)^2))/2 = ((4 + 2(16)) - (2 + 2(4)))/2 = ((4 + 32) - (2 + 8))/2 = (36 - 10)/2 = 26/2 = 13m/s.