In the pinewood-derby event shown, the car is released from rest at the starting positio...

In the pinewood-derby event shown, the car is released from rest at the starting position A and then rolls down the incline and on to the finish line C. If the constant acceleration down the incline is 9 ft/sec² and the speed from B to C is essentially constant, determine the time duration t_AC for the race. The effects of the small transition area at B can be neglected.