A ball of mass 1g and charge 10(—8) C moves from a point A where potential is 600V to a point B (potential is zero). Velocity of the ball at point B is 20cm/s. Velocity of the ball at point A is:

(plz answer with required steps)

Hello student

As we know only the electrostatic force is acting on the charged body, which is a conservative force.
Hence, the principle of conservation of Mechanical Energy holds true.

Ki + Ui = Kf + Uf
½ mv_A² + qV_A = ½ mv_B² + qV_B
½ x (0.001) x v_A² + 10^-8 x 600 = ½ x (0.001) x (0.2)² + 0

On solving, we get,
v_A = 0.1673 m/s = 16.73 cm/s

Hope it helps
Regards,
Kushagra