Question

if V(r)=(4/3)(pi)r^3 find

V(2r)
------
V(r)

I'm very confused on how to solve this function. Could someone guide me through this?

Answer 1

Please can some one help

Answer 2

since V is proportional to r^3,

V(2r)/V(r) = 2^3

gather all the constants into a single k, and you have

V(r) = kr^3
V(2r) = k(2r)^3 = k(2^3)(r^3) = 2^3*V(r)