question_answer

The adjacent figure is the part of a horizontally stretched net. section AB is stretched with a force of 10 N. The tensions in the sections BC and BF are

A) 10 N, 11 N                    

B) 10 N, 6 N

C) 10 N, 10 N

D) can't calculate due to insufficient data

Correct Answer: C

Solution :

By drawing the free body diagram of point B, let the tension in the section BC and BF are \[{{T}_{1}}\,\,and\,\,{{T}_{2}}\] respectively. From Lami?s theorem \[\frac{{{T}_{1}}}{\sin \,\,120{}^\circ }\,\,=\,\,\frac{{{T}_{2}}}{\sin \,120{}^\circ }\,\,=\,\,\frac{T}{\sin \,120{}^\circ }\] \[\Rightarrow \,\,T={{T}_{1}}={{T}_{2}}=10\,N\]