A drag racer crosses the finish line and the driver applies the brakes to slow down. The brakes are applied initially when to=9.0s and the car's velocity is 28m/s. When t=12s, the velocity has been reduced to 13m/s. What is the average acceleration of the dragster?

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.