Question

Two persons are holding a light rope tightly at its ends so that it is horizontal. A 15 kg weight is attached to the rope at the mid point which now no longer remains horizontal. The minimum tension required to completely straighten the rope is

• A. 45 kg
• B. $\frac{15}{2}$ kg
• C. 5 kg
• D. Infinitely large (or not possible)

Answer 1

The correct option is D Infinitely large (or not possible)

Since the weight is attached to rope at the center,

Thee rope won't be in horizontal anymore ,lets say it make angle $\theta$ with horizontal

So $2Tsin\theta =15g$,

To keep rope horizontal $\theta$ should be 0 , So tension must be infinitely large ,so that their product is =15g (practically this is not possible)