question_answer

The system is rotated with angular speed ox. (see figure). What is the ratio of energy stored in each wire?                

A) 31:9

B) 50:9  

C) 47:9

D) 8:9  

Correct Answer: B

Solution :

[b] \[{{T}_{1}}-{{T}_{2}}=m{{\omega }_{0}}^{2}(2l)\] \[{{T}_{2}}=m{{\omega }_{0}}^{2}(3l)\] \[\therefore \,\,{{T}_{1}}=5m{{\omega }_{0}}^{2}l.\] \[\frac{Energy(A)}{Energy(B)}=\frac{{{(stress)}^{2}}_{A}volume\,A}{{{(stress)}^{2}}_{B}\,volume\,B}\] \[=\frac{{{(5)}^{2}}}{{{(3)}^{2}}}\times \left( \frac{A\times 2l}{A\times l} \right)=\frac{50}{9}\]