Two identical balls, each possessing a charge of 2.00 10⁻⁷ C and a mass of 100 g , are suspended by two 50 cm long insulating strings from a common point. The balls are initially held 5.0 cm apart and subsequently released. Determine the components of the resultant force on one of the balls along and perpendicular to the string at the instant just after release.

Step-by-step solution

The forces acting on each ball are the tension T in the string, the gravitational force mg , and the electrostatic repulsion F_e . Just after release, the velocity of the balls is zero, which means the centripetal acceleration is zero. Therefore, the net force along the string is zero. The electrostatic force between the balls is: F_e = 1 4 ₀ q^2 d^2 = 9 10^9 (2.00 10⁻⁷)^2 (0.05)^2 = 0.144 N Let be the angle the string makes with the vertical. The distance from the vertical axis to each ball is d 2 = 2.5 cm . = 2.5