Question

Two particles of equal masses are revolving in circular paths of radii $r_{1}$ and $r_{2}$ respectively with the same speed. The ratio of their centripetal forces is

• A. $\frac{r_{2}}{r_{1}}$
• B. $\sqrt{\frac{r_{2}}{r_{1}}}$
• C. $\left( \frac{r_{1}}{r_{2}} \right)^{2}$
• D. $\left( \frac{r_{2}}{r_{1}} \right)^{2}$

Answer 1

Answer: (A)

$\frac{r_{2}}{r_{1}}$

Answer 2

$F = \frac{mv^{2}}{r}.$ If m and v are constants then $F \propto \frac{1}{r}$

∴ $\frac{F_{1}}{F_{2}} = \left( \frac{r_{2}}{r_{1}} \right)$