# Two balloons are charged with -0.0025 C each and held apart at a separation distance of 8 m. What is the magnitude of the electrical force of repulsion between them?

Feb 20, 2015

The answer is: $F = = 877 N$.

The low is:

$F = \frac{1}{4 \pi {\epsilon}_{0}} \frac{{q}_{1} {q}_{2}}{r} ^ 2$, or $F = {k}_{e} \frac{{q}_{1} {q}_{2}}{r} ^ 2$, where

${k}_{e} = 8 , 98 \cdot {10}^{9} {C}^{-} 2 {m}^{2} N$ is the constant of Coulomb.

So:

$F = 8 , 98 \times {10}^{9} {C}^{-} 2 {m}^{2} N \cdot \frac{\left(- 0.0025 C\right) \left(- 0.0025 C\right)}{8 m} ^ 2 = 877 N$.