A) \[a-b\]
B) \[5b-4a\]
C) \[2b-\frac{1}{4}a\]
D) \[4a-3b\]
Correct Answer: B
Solution :
Let L is the original length of the wire and K is force constant of wire. Final length = initial length + elongation \[L'=L+\frac{F}{K}\] For first condition \[a=L+\frac{4}{K}\] ?(i) For second condition \[b=L+\frac{5}{K}\] ?(ii) By solving (i) and (ii) equation we get \[L=5a-4b\] and \[K=\frac{1}{b-a}\] Now when the longitudinal tension is 9N, length of the string = \[L+\frac{9}{K}\]= \[5a-4b+9(b-a)\]\[x=5b-4a\].You need to login to perform this action.
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