Question

A uniform thick rope of length $10m$ and mass $10\,kg$ is resting on a horizontal frictionless surface. It is pulled by a horizontal force of $20\,N$ from one end. The tension in the rope at $2\,m$ from the end where the force is applied is,

• A. $4N$
• B. $8N$
• C. $16N$
• D. $20N$

Answer 1

Answer: (C)

The acceleration of the rope, $a=\frac{F}{m}=\frac{20}{10}=2\,ms^{- 2}$ .
The mass of the remaining portion of the $8\,m$ rope pulled by tension,
$m_{2}=\frac{M}{L}l_{2}=\frac{10}{10}\times 8=8\,kg$ .
Tension in the rope at $2\,m$ from the end where force is applied,
$T=m_{2}a$
$\Rightarrow T=8\times 2=16\,N$ .