1. The problem statement, all variables and given/known data A race car races on a circular racetrack of radius (r). (a) Write an equation for the car’s average speed when it travels a complete lap in time (t). (b) The radius of the track is 400m and the time to make a lap is 40s. Show that the average speed around the track is 63m/s. 2. Relevant equations Average Speed = Total Distance/ Travel Time 3. The attempt at a solution (a) speed = distance/time ? (b) 400m x 3.14 = 1256m. 63m/s = 1256m/40s.. this is where I get lost. This obviously isn't right. I'm getting an average speed of 31.4m/s.