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!!

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west