contestada

M is directly proportional to r squared
When r= 2, M= 14
a) Work out the value of M when r= 12.
b) Work out the value of r when M = 224.

Respuesta :

afiaboatemaa705

Step-by-step explanation:

[tex]m \alpha r ^{2} [/tex]

[tex]m = kr ^{2} [/tex]

[tex]14 = k \times 2 ^{2} [/tex]

[tex]14 = 4k[/tex]

[tex] \frac{14}{4} = k[/tex]

[tex]3.5 = k[/tex]

a.

[tex]m = kr ^{2} [/tex]

[tex]m = 3.5 \times 12^{2} [/tex]

[tex]m = 504[/tex]

b.

[tex]m = kr ^{2} [/tex]

[tex]224 = 3.5r ^{2} [/tex]

[tex] \frac{224}{3.5} = r ^{2} [/tex]

[tex]64 = r ^{2} [/tex]

[tex] \sqrt{64} = \sqrt {r}^{2} [/tex]

[tex]8 = r[/tex]