A spiral spring has a length of 14cm when a force of 4N is hung on it. A force of 6N extends the spring by 4cm. Calculate the unstretched length of the spring
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Correct Answer: Option n
Explanation:
Using hookes law
\(\frac{F_1}{e_1} = \frac{F_2}{e_2}\)
but e\(_1\) = l\(_1\) = l\(_o\)
\(\frac{F_1}{l_1 - l_o}\) = \(\frac{F_2}{e_2}\)
\(\frac{4}{14 - \_o}\) = \(\frac{6}{4}\); 16 = 6(14 - \(_o\))
14 = 84 - 6\(l_o\); 16 - 84 = -6\(l_o\)
\(l_o = \frac{-68}{-6}\) = 11.33cm
Using hookes law
\(\frac{F_1}{e_1} = \frac{F_2}{e_2}\)
but e\(_1\) = l\(_1\) = l\(_o\)
\(\frac{F_1}{l_1 - l_o}\) = \(\frac{F_2}{e_2}\)
\(\frac{4}{14 - \_o}\) = \(\frac{6}{4}\); 16 = 6(14 - \(_o\))
14 = 84 - 6\(l_o\); 16 - 84 = -6\(l_o\)
\(l_o = \frac{-68}{-6}\) = 11.33cm