A negative point charge -Q is at the center of a hollow insulating spherical shell, which has an inner radius R1 and an outer radius R2. There is a total charge of +4Q spread uniformly throughout the volume of the insulating shell, not just on its surface.

Determine the electric field for the following. (Use any variable or symbol stated above along with the following as necessary: r and Eo )

a) r
b) R1
c) R2

see the answers below

Explanation:

we can use a Gaussian's surface to calculate E:

Where Q is the net charge inside the Gaussian' s surface

Hence, we have

a)

for r:

b)

for R1, the Gaussian's surface has a charge of -Q (the charge at the center):

c)

for R2, the net charge inside the Gaussian's surface is -Q+4Q=+3Q, hence:

HOPE THIS HELPS!!

the closer the planet is to the sun, the larger the gravity

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg