The mass, m, of an object varies directly as the cube of its length, I.
m= 250 when I = 5.
Find m when I = 7

m = 686.

Step-by-step explanation:

Direct variation :

m= kl^3 where k is a constant.

m = 250 when l = 5, so

250 = k *(5)^3

k = 250 / 125 = 2

So the equation of variation is m = 2l^3.

When l = 7:

m = 2 * (7)*3

= 2 * 343

= 686.

step-by-step explanation:

i believe the answer is d.

hope it you! : d