1. The problem statement, all variables and given/known data 16. A car completes a horizontal circle of radius r in time T. The same car then completes a larger horizontal circle of radius 2r in half the time. What is the ratio of the centripetal acceleration ac for the car in the second circle to that in the first circle a c2 a c1? 3. The attempt at a solution iv never understood the whole ratio thing i got (4pi^2*4R)/(T^2/4) the answer is suppose 2 be 8:1 so i assume the second car is the 8 Ithink i got it actually (4pi^2*2R)/(T^2/4):(4pi^2*R)/T^2 that 8:1 did i do it right?