## anonymous one year ago two point charges of +5.0 * 10^-5 C and -5.0 * 10^-5 C are separated by 0.50 m. Which of the following describes the force between them? A. 90 N , attractive B. 45 N, repulsive C. 45 N , attractive D. 90 N , repulsive

1. Michele_Laino

that force is attractive, since the charge have opposite sign

2. anonymous

yes:) how can we find if it is 45 or 90?

3. Michele_Laino

furthermore, we have to apply the Coulomb law: $\Large F = K\frac{{{Q_1}{Q_2}}}{{{r^2}}} = 9 \times {10^9}\frac{{5 \times {{10}^{ - 5}} \times 5 \times {{10}^{ - 5}}}}{{{{\left( {0.5} \right)}^2}}}$

4. anonymous

so we get 90? so option A is our solutoin?

5. Michele_Laino

yes! correct!

6. anonymous

yay!:)thanks!! okay onto the next! :P

7. Michele_Laino

:)