Question

M is directly proportional to r 2squared when r =2 m=14
work out the value of m when r=12
work out the value of r when m=224

Answer 1

m = 504 if r = 12  & r = ±8 if m = 224   given that m ∝  r² & m = 14 at r = 2

Step-by-step explanation:

m ∝  r²

=> m = kr²

k is constant

when r = 2  m = 1

=> 14 = k (2)²

=> 14 = 4k

=> k = 14/4

=> k = 7/2

m = kr²

r = 12

=> m  = (7/2)12²

=> m = 504

m = 224

224 = (7/2)r²

=> r² = 64

=> r = ± 8

Learn more:

m is directly proportional to r cubed, when r=4 m=160, work out the ...

https://brainly.in/question/12856748

If Y is directly proportional to X and Y = 24 when X = 10, then find the ...

https://brainly.in/question/8160898

Answer 2

Answer:

r=8

Step-by-step explanation: