4) Refer to the image showing a roller coaster track. To make this roller coaster scary, engineers have designed the roller coaster car to begin at rest at point A and reach a speed of 21.0 m/s at point C. The mass of the roller coaster car is 2530 kg. [K3, T4]

a.What must be the height of the first hill in order for the coaster to reach the speed of 21.0 m/s at point C? [T4] b. If there was friction along the roller coaster track, would this change the height of point A? Would the height stay the same, be larger, or smaller? Explain. [K2] At which point does the roller coaster reach the maximum speed? [K 1]