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Show dimensionally that the relation `t = 2pi((I)/(g))` is incorrect, where I is length and t is time period of a simple pendulum , g is acc. Due to gravity. Find the correct form of the relation, dimensionally |
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Answer» `RHS = 2pi((I)/(g)) = (L)/(LT^(-2))` `=T^2 != t(LHS)` :. Formula is incorrect Let `t =k l^a g^b …..(i)` `[M^0L^0T^1] = L^a (LT^(-2))^b = L^(a +b) T^(-2b)` Using principle of homogeneity of dimensions, ` a +b =0, -2b =1, b = -(1)/(2)` `:. a =-b =- (-(1)/(2)) = (1)/(2)` From (i), `t = kl^(1//2) g^(-1//2) = k sqrt((I)/(g))` |
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