Mis directly proportional to r2.when r=2,m=14.work out the value of r when m =224

r = 8

Step-by-step explanation:

Given that M is directly proportional to r² then the equation relating them is

M = kr² ← k is the constant of proportionality

To find k use the condition when r = 2 , M = 14

k = = =

M = r² ← equation of proportion

When M = 224, then

224 = r² ← multiply both sides by 2

7r² = 448 ( divide both sides by 7 )

r² = 64 ( take the square root of both sides )

r = = 8

it should be a and d. lmk if i'm wrong xd