Question:
A spherical shell is made from a thin sheet of material with a mass per area of σ. Consider two points, P1 and P2, which are close to each other, but just inside and outside the sphere, respectively. If the accelerations due to gravity at these points are g1 and g2, respectively, what is the value of ∣g1−g2∣?
(A) πGσ.
(B) 4πGσ/3.
(C) 2πGσ.
(D) 4πGσ.
(E) 8πGσ.