devarshi-dt-logo

Question:

An L-shaped object, made of thin rods of uniform mass density, is suspended with a string as shown in figure. If AB=BC, and the angle made by AB with the downward vertical is θ, then:

tanθ=2√3

tanθ=13

tanθ=12

tanθ=12√3

Solution:

Let the mass of one rod be m.
Balancing torque about the point
mg(C1P) = mg(C2N)
mg(L/2sinθ) = mg(L/2cosθ - Lsinθ)
→ 3/2mgLsinθ = mgL/2cosθ
→ tanθ = 1/3