Question

A mass is supported on a frictionless horizontal surface. It is attached to a string and rotates about a fixed centre at an angular velocity ${\omega }_0$. If the length of the string and angular velocity are doubled, the tension in the string which was initially $T_0$ is now

• A. $T_0$
• B. $\frac{T_0}{2}$
• C. $4T_0$
• D. $8T_0$

Answer 1

The correct option is D

$8T_0$

Tension in the string $T_0=mR{\omega }_0^2$
In the second case $T=m\left(2R\right)\left(4{\omega }_0^2\right)=8mR{\omega }_0^2=8T_0$