Question

A thin plastic spherical shell with radius 5 cm has a charge Q = 2 e (where e is the charge of a proton) distributed evenly over its surface. At the center of the hole is a point charge q = -2 e.

What would be the force on a point charge of 1.1 e displaced < 0, 2.9, 0 > cm from the point charge q?

< 0, -6.0e-25, 0 > N

< 0, 6.0e-25, 0 > N

< 0, -2.4e+13, 0 > N

< 0, -6.0e-29, 0 > N

< 0, -6.7e-35, 0 > N

Answer 1

The charge on the spherical shell is on the surface, and we know electric field inside the shell due to charge on surface is zero.

For for any charge inside the shell, it will not experience any force from the charge on the surface,

Here there are teo charge inside the shell

One is at centre of shell

,The other is at 2.9cm along y axis in the shell

So in other ways the distance between the these two charges are 2.9cm.

So , F = kq1q2/r^2

F = 9×10^9 ×(-3)×(1.1)/(.029)^2

F= 2.354 ×10^13

F = 2.4×10^13