On x-axis age of the baby
on y-axis weight of the baby
As we know that electric field at any point caused due to a point charge given by, kQ/r^2
Where, k is dielectric constant of medium, Q is the point charge and r is the distance between the point charge and point where electric field is to be measured.
Let us assume a charge of q is placed at x=+20cm to make electric field at
x=+10cm zero.
Total electric field at x=+10cm can be shown by equation,
(k X 2.20 X 10^-12)/(10-0)^2 + (k X -4.80 X 10^-12)/(10-(-11))^2 + (k X
q)/(10-20)^2 = 0
=> 2.20 X 10^-14 - 1.09 X 10^-14 + q X 10^-2 = 0
=> q = 1.09 X 10^-12 - 2.20 X 10^-12
=> q = -1.1 X 10^-12 Coulombs or -1.1 pC
Explanation:
If q is the charge on ball 1 and q' is the charge on other ball. At a moment if one of the ball kept positively charged and the charge on the other ball were slowly increased, the amount of change on second ball increases. As a result, the two ball moves very far apart from each other.
Also, if the magnitude of charge increases, the force of repulsion acting between them increases. Hence, this is the required solution.