Question

Two small, metallic spheres are charged, with charges of -2uc and 4uc respectively. The spheres are touched together, resulting in a transfer of charges, and then placed  apart. To three significant figures, determine:

a) the final charge on each sphere. (1 pt)

b) the number of charges that are transferred from one sphere to the other. (1 pt)

c) the magnitude of the force that acts on one of the spheres after they are touched and separated. (1 pt)

Answer 1

let Q1 = -2 micro C
Q2 = 4 micro C

a) The final charge on each sphere, Q = (Q1 + Q2)/2

= (-2 + 4)/2

= 1 micro C <<<<<--------------Answer

b) the number of charges(electrons) transfrred from one sphere to the other, N = delat_Q/e

= (Q2 - Q)/e

= (4 - 1)*10^-6/(1.6*10^-19)

= 1.875*10^-13 electrons <<<<<--------------Answer

c) The magnitude of the force that acts one of the spheres,

F = k*Q^2/d^2

= 9*10^9*(1.6*10^-6)^2/d^2

= 0.02304/d^2

substitude distance(d) between the two sphere in the above equation to get the answer.