Question

A car travels around a level circular track of radius r at a constant velocity. If the radius of the track is increased to 6r and the velocity of the car remains the same, which of the following represents the new centripetal force?(a) Six times the original centripetal force(b) Three times the original centripetal force(c) One-sixth the original centripetal force(d) One-third the original centripetal force

Answer 1

`\begin{gathered} f_c=(mv^2)/(r) \\ m=\text{mass} \\ v=\text{velocity} \\ r=\text{radius} \end{gathered}`

Therefore,

The new change will be

new radius = 6r

Therefore, the centripetal force will be

`\begin{gathered} f_c=(mv^2)/(6r) \\ \text{ multiply both sides by 6} \\ 6f_c=(mv^2)/(r) \end{gathered}`

Therefore, the answer will be A.