anonymous 3 years ago Pleaseeee help me.. What is the electric force between a +2 µC point charge and a –2 µC point charge if they are separated by a distance of 5.0 cm? (µC = 1.0 × 10–6 C)

1. anonymous

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2. anonymous

F = Kq1q2/r^2

3. anonymous

Coulomb's Law: $F=K{q_1q_2\over d^2}$ $K = const.\\ q_1 = 2\times10^{-6}C\\ q_2= 2\times10^{-6}C\\ d=5{\rm cm}\times {1{\rm m}\over 100{\rm cm}}=0.05{\rm m}$

4. anonymous

the important thing is to have all the units in SI system

5. anonymous

So i had to put cm into m like i believe you did above?

6. anonymous

yep

7. anonymous

now from here where do I go?

8. anonymous

wouldnt q2 be negative?

9. anonymous

we plug em in the equation for the force. $F=8.99\times10^{9}\times \frac{2\times10^{-6}\times2\times10^{-6}}{(0.05)^2}$

10. anonymous

the negative sign can be neglected since we are only looking for the magnitude (i.e., the amount) of force. since the two charges are oppositely charged, the above force will be a force of attraction. this is the information we get from the charges

11. anonymous

Okay cool so then Id just plug the above into my calculator and thats the answer. right?