Question

Two small tiny conducting spheres, both initially having no charge, are brought into contact and given a total charge of 5.00x10^4 electrons. The spheres are then pulled apart until their centers are 12.0 cm apart. Assume the total number of electrons on the spheres remained the same as they were separated. a) what is the magnitude of the force that each sphere exerts on the other? b) Is the force attractive or repulsive?

Answer 1

(A)
`10^(-17)N`

(B) Repulsive force

Step-by-step explanation:

We have given total charge on both spheres
`=5* 10^4electron`

Charge on 1 electron
`=1.6* 10^(-19)C`

So total charge
`=5* 10^4* 1.6* 10^(-19)=8* 10^(-15)C`

Charge on both the sphere will be equally distributed

So charge on individual sphere
`=(8* 10^(15)C)/(2)=4* 10^(1-5)C`

Distance between both the spheres = 12 cm = 0.12 m

According to coulombs law force between two charges is given by
`F=(1)/(4\pi \epsilon _0)(Q_1Q_2)/(R^2)=(KQ^2)/(R^2)=(9* 10^9* (4* 10^(-15))^2)/(0.12^2)=10^(-17)N`

(B) As the charge on both the sphere is of same sign so force will be repulsive