Question

1. Two identical copper spheres of radius R are
in contact with each other. If the gravitational
attraction between them is F, find the relation
between F and R.
(a) F« R4
(b) Fo R3/2
(c) Foc R-2
(d) F« R 4​

Answer 1

Answer:

d

Explanation:

Mass of each sphere  M1=M2=ρ(34πR3)

Gravitational force between them is given by F=(2R)2GM1M2

F=4R2G×34πR3ρ×34πR3ρ=94π2Gρ2R4

So F∝R4.