A minibus drives 238 miles with a constant speed of 84 mph and another 80 miles with a constant speed of 60 mph. how much time in total does it take to travel these distance?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?