Rankers Physics
Topic: Laws of Motion
Subtopic: Equilibrium based Questions

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:
150 N
50 N
75 N
Infinitely Large (or Not Possible)

Solution:

For Equilibrium condition,

2T cos θ = mg ⇒ T = mg/(2 cos θ)

As, we try to make string horizontal θ approaches 90°. so Tension will become T= mg/2 cos (90°)

i.e    T  becomes infinite

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