Question

The mass of a cube,

M
(kg), is proportional to the cube of the length of its edge,
L
(m).
The mass of the cube is 90 kg when the length of its edge is 20 cm.
Work out
L
(to 2 DP) when
M
=
1700
kg

Answer 1

Below

Explanation:

m = k l^3 <=======given

when m = 90 kg and l = 20 cm

90 = k (20^3) shows k = .01125 kg/cm^3

sooooo : m = .01125 l^3

when m = 1700:

1700 = .01125 l^3

l = cubrt ( 1700/.01125) = 53.26 cm