Answer:
[tex]d = \dfrac{3}{16}[/tex]
Step-by-step explanation:
c varies jointly with d and the square of g
[tex]c\propto dg^2[/tex]
[tex]c=kdg^2[/tex]
where, k is constant of proportionality.
Put the given value c = 30 when d = 15 and g = 2 and find out k
[tex]30=k\cdot 15\cdot 2^2[/tex]
[tex]k=\dfrac{1}{2}[/tex]
[tex]c=\dfrac{1}{2}kg^2[/tex]
If c = 6 and g = 8 then d = ?
[tex]6=\dfrac{1}{2}\cdot d\cdot 8^2[/tex]
[tex]d=\dfrac{6\cdot 2}{8^2}[/tex]
[tex]d=\dfrac{3}{16}[/tex]
Hence, The value of d is [tex]\dfrac{3}{16}[/tex]