Question

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

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

Answer 1

The correct option is D $16ML$

Given : $w=\frac{2}{\pi }$ rev. per sec $⟹w=2\pi \nu =4$

From figure $R=Lsin\theta$

$\therefore$ $Tsin\theta =MR{w}^2$

$⟹$ $T=ML{w}^2=ML(4{)}^2=16ML$