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                                   [KCET 2005]

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             \[\frac{{{T}_{1}}}{\sin 120{}^\circ }=\frac{{{T}_{2}}}{\sin 120{}^\circ }=\frac{T}{\sin 120{}^\circ }\]               Þ \[T={{T}_{1}}={{T}_{2}}=10\ N.\]