Question

A rope of length 5 m is kept on frictionless surface and a force of 5 N is applied to one of its end. Find the tension in the rope at 3 m from the other end.

• A. 1 N
• B. 3 N
• C. 4 N
• D. 5 N

Answer 1

The correct option is C 4 N

Let the mass of the rope is M

so the acceleration of the rope is given as

So the whole rope is moving with above acceleration

Now the mass per unit length of the rope is given as

$m=\frac{M}{5}$

now we have the mass of 4 m rope which is 1 m from the end where we applied the force is given as

$m^{\prime }=\frac{M}{5}\ast 4=0.8M$

now the tension force at that end is given as

$\begin{array}{c}T=m^{\prime }\times a\\ T=0.8M\times \frac{5}{M}\\ T=4N\end{array}$

so it required 4 N tension at that position

Hence,

option $C$ is correct answer.