A string of area of cross-section \(4\,mm ^{2}\) and length \(0.5\) is connected with a rigid body of mass \(2\,kg\). The body is rotated in a vertical circular path of radius \(0.5\,m\). The body acquires a speed of \(5\,m / s\) at the bottom of the circular path. Strain produced in the string when the body is at the bottom of the circle is \(\ldots . . \times 10^{-5}\). (Use Young's modulus \(10^{11}\,N / m ^{2}\) and \(g =10\,m / s ^{2}\) )

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Answer & Solution

Correct Answer

(C) \(30\)

Step-by-step Solution

Detailed explanation

Strain \(=\) F/AY

\(=\frac{ mg +\frac{ mv ^{2}}{ R }}{ AY }\)

\(=\frac{20+\frac{2(5)^{2}}{0.5}}{3 \times 10^{-6} \times 10^{11}}=30 \times 10^{-5}\)

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