Question

A straight of length L is fixed at one end and carries a mass M at the other end. The string makes $\frac{2}{\pi }$ revolution per second around the vertical axis through the fixed end as shown in the figure, then tension in the string is?

• A. ML
• B. $2$ML
• C. $4$ML
• D. $16$ML

Answer 1

The correct option is D $16$ML

lenght of string I

mass M

angular speed W

$=\frac{2}{\pi }revolution/second$

$\frac{2\times 2\pi }{\pi }rad/sec=4rad/sec$

$tensionT=\frac{{Mv}^2}{r}=Mr{\omega }^2=ML\times 4\times 4=16MLnewton$