Apparent WeightlessnessMediumQuestion 30629
Question
On a roller coaster at the top of a loop (radius r), a person feels weightless when:
- AThe speed is very low
- Bmg = mv²/r (normal force is zero)Correct
- CThe person is not strapped in
- DThe loop is very large
Correct answer
mg = mv²/r (normal force is zero)
Explanation
Weightlessness means N = 0. At the top: mg + N = mv²/r. For N = 0: v = √(gr).