Question

m is directly proportional to r cubed, when r=4 m=160, work out the value of m when r=2

Answer 1

Answer:

m = 20

Step-by-step explanation:

m ∝  r³

=> m = kr³

r=4 m=160

=> 160 = k (4)³

=> k = 160 / 64

=> k = 2.5

m = 2.5 r³

r = 2

=> m = 2.5 * 2³

=> m = 20