Question

A stone of mass $1$ kg tied to a light inextensible string of length $:=\frac{10}{3}$m, whirling in a circular path in a vertical plane. The ratio of maximum tension in the string to the minimum tension in the string is $4$, if g is taken to be $10$ $m/s^2$, the speed of the stone at the highest point of the circle is?

• A. $10$ m/s
• B. $5\sqrt{2}$ m/s
• C. $10\sqrt{3}$ m/s
• D. $20$ m/s

Answer 1

The correct option is A $10$ m/s

Ratio of maximum tension is $T_2=4T$

Different of two tensions will be 6 mg

$T_1$= 2mg

Now tension at the top of right circle is

$T_1=\frac{M{v}^2}{r}$

$V_1=\sqrt{10}g$$=\sqrt{10\ast 10}$ $=10m/s$