- #1

tmichaud26

- 3

- 1

- Homework Statement
- Two small spheres spaced 20.0 cm apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 3.33×10^−21N?

- Relevant Equations
- Charge of an electron e=-1.6X10^-19 C

F=kq/(r^2)

**Homework Statement:**Two small spheres spaced 20.0 cm apart have equal charge. How many excess electrons must be present on each sphere if the magnitude of the force of repulsion between them is 3.33×10^−21N?

**Homework Equations:**Charge of an electron e=-1.6X10^-19 C

F=kq/(r^2)

For this I set the force equal to 3.33X10^-21N and solved for the value of q given that we know the values for k (9x10^9Nm^2/C^2) and r=0.2m. This gave a q value of 1.48x10^-31 which I then divided by the charge of an electron to get a value of 9.25x10^-14 which is not an appropriate value for number of electrons. Am I using the correct equation?