Question

A mass is supported on a frictionless horizontal surface. It is attached to a string and rotates fixed center at an angular $velocit{y}_{{\omega }_o}$ If the length of the string and angular velocity are douted tension in the string which was initially $T_o$ is now,

• A. $T_o$
• B. $T_o/2$
• C. $4T_o$
• D. $8T_o$

Answer 1

Answer: (D)

$8T_o$

Tension in the string $T_0=mR{\omega }_0^2$

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

Hence,

option $\left(D\right)$ is correct answer.