Question

A woman travels over the top of a circular shaped hill on roller coaster so that she momentarily experiences the feeling of weightlessness at the very top of the hill. At this point. what is the woman's acceleration?

• A. $0m/s^{2}verticallyonly$
• B. $0m/s^{2}verticallyandhorizontally$
• C. $9.80m/s^{2}downwardonly$
• D. $9.80m/s^{2}upwardonly$
• E. We need to know the radius of the truck and the speed of the coaster to answer this question.

Answer 1

Answer: (C)

$9.80m/s^{2}downwardonly$

At the very top of the hill forces acting on the woman are Normal by the earth, earth's gravity. Her acceleration is towards center of circular path. Since she is experiencing weightlessness the normal force by earth on woman must be zero as normal force is equal to the apparent weight of the woman. So now only force acting on her is mg downwards. And thus, her acceleration is g downwards.