1. The problem statement, all variables and given/known data http://img98.imageshack.us/img98/7256/circularhn0.png [Broken][/URL] 2. Relevant equations None. 3. The attempt at a solution The answer key says that the answer is the bus coming to a stop. I think this is the answer because the wheels of the bus are slowing down. Is this the right answer, because a lot of people in my class thought that the answer was the earth revolving the sun, even though the earth revolves around the sun in an elliptical orbit and not a circular one.