Question

Two persons are holding a rope of negligible weight 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. 15 kg
• B. 15/2 kg
• C. 5 kg
• D. Infinitely large

Answer 1

The correct option is D Infinitely large

The tension required to bring the string into horizontal position can be found out using the

following formulae.

$2Tsinx=mg$

The following equation is true for body which attains equilibrium. Also, when the body will

be in equilibrium the angle formed will be 0.

Therefore,

$T=mg/2sinx,$ where $x=0$

$T=mg/2sin0,$ where the value of $sin=0$

Then, the amount of tension required is infinite.