1. The problem statement, all variables and given/known data On a straight road you start your car and increase the speed at a steady rate to 45 miles per hour during a 5 second interval. Calculate: a)the average speed during the 5 seconds b) the acceleration in miles per second at t = 3.2 sec. after you start your car c) the speed of the car at t = 2.5 sec. d) the time when the speedometer will read the average speed you calculated for part a) as the instantaneous speed. 2. Relevant equations Ave. speed = Vf + Vo/2 = (45 mi/hr + 0 mi/hr)/2 = (45mi/hr)/2 = 22.5 mi/hr 3. The attempt at a solution Ave. speed = Vf + Vo/2 = (45 mi/hr + 0 mi/hr)/2 = (45mi/hr)/2 = 22.5 mi/hr The speed of the car at t = 2.5 seconds is: change in distance divided by change in time I am not sure how to find the acceleration, or the time when the speedomoter will read the average speed in part a) as the instantaneous speed.