Question

A simple pendulum of mass (m)having length (l).What should be workdone on the Bob to make angle of deflection 45°?​

Answer 1

Explanation:

We can take the answer for this by applying F = ma to the bob vertical and horizontal directions,

Since the bob is not moving and it is balanced by the forces,when we apply the equation vertically, we will get,

TCos∅ = mg -----------------(1)

And Horizontally,

TSin∅ = Eq ------------------(2) ,  E - Electric Field Density of the Sheet

by (2)/(1),

Tan∅ = Eq/mg

We can Replace E by σ/ε where ε is the permittivity of a vaccum and it is a constant,

Then we can write,

Tan∅ = σq/εmg

Then,

∅ = Tan Inverse (σq/εmg)