Home » T varies inversely as the cube of R. When R = 3, T = (frac{2}{81}),…

T varies inversely as the cube of R. When R = 3, T = (frac{2}{81}),…

T varies inversely as the cube of R. When R = 3, T = (frac{2}{81}), find T when R = 2
  • A.
    (frac{1}{18})
  • B.
    (frac{1}{12})
  • C.
    (frac{1}{24})
  • D.
    (frac{1}{6})
Correct Answer: Option B
Explanation

T (alpha frac{1}{R^3})
T = (frac{k}{R^3})
k = TR3
= (frac{2}{81}) x 33
= (frac{2}{81}) x 27
dividing 81 by 27
k = (frac{2}{2})
therefore, T = (frac{2}{3}) x (frac{1}{R^3})
When R = 2
T = (frac{2}{3}) x (frac{1}{2^3}) = (frac{2}{3}) x (frac{1}{8})
= (frac{1}{12})

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