Question

A particle of mass $100g$ tied to a string is rotated along a circle of radius $0.5m$. The breaking tension of string is $10N$. The maximum speed with which particle can be rotated without breaking the string is (in $m/s$)

• A. $7.07$
  
• B. $7.7$
  
• C. $5$
  
• D. $6$
  

Answer 1

The correct option is A $7.07$

As given that breaking tension of string is $10N$ so the tension in the string when we rotate the mass should be less than $10N$

$\Rightarrow T\ge m\frac{v^2}{R}\Rightarrow v\le \sqrt{\frac{TR}{m}}$

given that $m=100g=0.1kg$, $R=0.5m$

$\Rightarrow v\le \sqrt{\frac{10\times 0.5}{0.1}}$

$\Rightarrow v\le \sqrt{50}\Rightarrow v\le 7.07m/s$