On a straight track, a cart travels with a constant velocity of 2.5m/s for 9.0s. It then uniformly accelerates to a final velocity of 6.0m/s in 15s. Calculate the total distance travelled by the cart.
Vavg = Vi+Vf/2
d=Vi x t + 1/2at^2
The Attempt at a Solution
I tried finding the average velocity by adding together 6.0 and 2.5 before dividing it by 2 to get 4.25. Then, I multiplied that number by the total time of 24s (15+9). This got me the number 102, but the answer key says the answer is 86?