a 0.482 kg toy car is powered by four aa batteries (6.00 v total) connected directly to a small dc motor. the car has an effective energy conversion efficiency of 47.1%, meaning that 47.1% of the electric energy applied to the motor is converted into translational kinetic energy. after 7.88 s , the car, which is initially at rest, reaches a speed of 2.35 m/s. what is the average current supplied to the car's motor?