• A designer is working on a new roller coaster, and she begins by making a scale model. In this model ,a car of total mass m=0.5kg moves with negligible friction along the track shown. The car is given an initial speed v0 = 1/5 m/s at the top of the first hill of height 2 m. Point A is located at a height of 1.9 m at the top of the second hill, the upper part of which is a circular arc of radius 0.95 m.
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• (a) Calculate the speed of the car at point A.
• (b) In order to stop the car at point A, some friction must be introduced. Calculate the work that must be done by the frictional force to stop the car at point A.
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0.50 kg 2.0 m = 1.5 m/s r=0.95 m 1.9 m 0.50 kg 2.0 m = 1.5 m/s r=0.95 m 1.9 m