Question

A mass of 100 gm is tied to one end of a string 2 m long. The body is revolving in a horizontal circle making a maximum of 200 revolutions per min. The other end of the string is fixed at the centre of the circle of revolution. The maximum tension that the string can bear is (approximately)

• A. 8.76 N
• B. 8.94 N
• C. 89.42 N
• D. 87.64 N

Answer 1

The correct option is

B

87.64 N

m=100g =0.1kg
and R=2m
Frequency=200 rotation per minute
$f=\frac{200}{60}=3.33Hz$

Angular velocity $\left(\omega \right)=2\pi f$ $=2\times \pi \times 3.33=20.9rad/s$

Maximum tension= $m{\omega }^{2}R=m\times (\omega {)}^2\times R$ = $0.1\times 2\times (20.9{)}^2=87.64N$
$T_{max}=87.64N$