Charged pendulum

Classical Mechanics Level 5

Two point charges, each of charge q and mass m, are hung from 1 m long cords and constrained to move in a 2-d plane (so they can swing but not rotate). The charge and mass are chosen such that the when the charges are in their equilibrium position the angle $$\theta_0$$ the cords make with the vertical is 0.1 radians. The masses are placed in their equilibrium positions and then each is pulled out by some small angle $$\Delta \theta=0.01$$ radians and released. What is the period of the resulting oscillation in seconds?

Details and assumptions

• The acceleration of gravity is $$-9.8~m/s^2$$.
×