Question

Two balloons are charged with an identical quantity and type of charge:-4 nC. They are held apart at a separation distance of 70 cm. Determine the magnitude of the electrical force of repulsion between them.

Answer 1

Answer:

$2.9\cdot 10^{-7}N$

Explanation:

The electrostatic force between the two balloons is given by:

$F=k\frac{q_1 q_2}{r^2}$

where

$k=9\cdot 10^9 Nm^2 C^{-2}$ is the Coulomb's constant

$q_1=q_2=-4 nC=-4\cdot 10^{-9}C$ is the charge on each balloon

$r=70 cm=0.7 m$ is the distance between the balloons

Substituting into the formula, we find

$F=(9\cdot 10^9 Nm^2C^{-2})\frac{(-4\cdot 10^{-9}C)^2}{(0.70 m)^2}=2.9\cdot 10^{-7}N$