question_answer

A man grows into a giant such that his linear dimensions increase by a factor of 9. Assuming that his density remains same, the stress in the leg will change by a factor of:                                      [JEE Main 2017]

A)  81       

B) \[\frac{1}{81}\]

C)  9                    

D)       \[\frac{1}{9}\] Correct Answer: C Solution : [c] \[Stress=\frac{Force}{area}=\frac{mg}{A}\]

\[=\frac{volume\times density\times g}{Ara}\]

\[Stress=\frac{{{L}^{3}}\rho g}{{{L}^{2}}}\]