Question

A chain of 125 links is 1.25 m long and has a mass of 2 kg. With the ends fastened together, it is set rotating at 3000 rev/min. The centripetal force on each link is :

• A. 3.14 N
• B. 314 N
• C. $\frac{1}{3.14}$ N
• D. $\frac{1}{314}$ N

Answer 1

The correct option is B 314 N

Angular velocity :

$\omega =3000$ rpm

$=\frac{2\pi }{60}\times 3000$ rad/s

$=100\pi$

Mass of each link :

$m=\frac{2}{125}kg$

Radius of circular path :

$r=\frac{L}{2\pi }$

$=\frac{1.25}{2\pi }$

Total Centripetal force :

$F=m{\omega }^{2}r$

$=\frac{2}{125}\times [100\pi {]}^2\times \frac{1.25}{2\pi }$

$=314N$