The elongation of a wire on the surface of the earth is 10$-$4 m. The same wire of same dimensions is elongated by 6 $\times$ 10$-$5 m on another planet. The acceleration due to gravity on the planet will be ____________ ms$-$2. (Take acceleration due to gravity on the surface of earth = 10 ms$-$2)
Answer (integer)
6
Solution
<p>on earth, $\Delta l = {10^{ - 4}}\,m$</p>
<p>on other planet $\Delta l' = 6 \times {10^{ - 5}}\,m$</p>
<p>$$\Delta l = {{Fl} \over {Ay}} \Rightarrow {{\Delta l'} \over {\Delta l}} = {{{{F'l} \over {Ay}}} \over {{{Fl} \over {Ay}}}} = {{mg'} \over {mg}}$$</p>
<p>$\Rightarrow g' = {{\Delta l'} \over {\Delta l}} \times g$</p>
<p>$= {{6 \times {{10}^{ - 5}}} \over {{{10}^{ - 4}}}} \times 10$</p>
<p>$\Rightarrow g' = 6$ m/s<sup>2</sup></p>
About this question
Subject: Physics · Chapter: Properties of Solids and Liquids · Topic: Elasticity
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