Question

The CN Tower, in Toronto, Canada, is 553 m tall. Suppose two balls, each with a mass of
5.00 kg and a charge of 40.0 mC, are placed at the top and bottom of the tower, respectively.
The ball at the top is then dropped. At what height is the acceleration on the ball zero?

Answer 1

Answer

This is question related to equilibrium.

When the acceleration on the ball is zero then force due to gravity and electrostatic force should be equal.

$mg=\frac{kqq'}{r^2}$

$5\times9.8=\frac{9\times10^9\times40\times40\times10^{-6}}{r^2}$

So distance between charges or height

r=550.60m