Acar leaves a garage at 10 mph. it speeds up to 20 miles per hour in the city and eventually increases to 50 miles per hour in the country. overall, the car went 50 miles during 1.5 hours of travel time. what was the car's average speed

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.