Question

A chain of $125$ links is $1.25m$ long and has mass of $2kg$ with the ends fastened together. It is set for rotating at $50$ revolutions per second. The centripetal force on each link is

• A. $3.14N$
• B. $0.314N$
• C. $314N$
• D. None of these

Answer 1

Answer: (C)

circumference $=2\pi r=1.25m$
so radius $r=\frac{1.25m}{2\pi }=0.199m$
Mass of each link is m $=\frac{2kg}{125}$ $=0.016$ $kg$
angular velocity is $w=50$ revolutions per second = $50\times 2\pi rad{s}^{-1}=314rad{s}^{-1}$
The centripetal force on each link is $f=m\times r\times w^2=\left(0.016\times 0.199\times 314^2\right)\mathrm{N}$
$f=314$ $N$