Question

If the speed of revolution of a particle on the circumference of a circle and the speed gained in falling through a distance equal to half the radius are equal, then the centripetal acceleration will be

• A. $\frac{g}{2}$
• B. $\frac{g}{4}$
• C. $\frac{g}{3}$
• D. g

Answer 1

Answer: (D)

g

Answer 2

Speed gain by body falling through a distance h is equal to $v = \sqrt{2gh}$ $= \sqrt{2g\frac{r}{2}}$ [As $h = \frac{r}{2}$ given]

⇒ $v = \sqrt{gr}$ ⇒ $\frac{v^{2}}{r} = g$