Question

M is directly proportional to R cubed a)R = 4, M = 160 find M when R = 2 b) work out the value of R when M=540

Answer 1

a k (proportionality constant) = 2.5

b. r = 6

Explanation:

Here, we want to solve a variation

m = k * r^3

160 = k * 4^3

160 = 64k

k = 160/64

k = 2.5

b) secondly;

From;

540 = 2.5 * r^3

r^3 = 216

r = cube root of 216

r = 6