question_answer

Two forces 50 N and 100 N are acting on a rod capable of rotating it about 0 as shown in Mg. 5(HT).l What is the net torque acting on the rod?       

Answer:

                In Fig. 5(HT).1, we have resolved force of 100 N into two rectangular components: \[100\,\cos {{30}^{\text{o}}}\]along the horizontal  and \[100\,\cos {{30}^{\text{o}}}\] along the vertical. The horizontal component cannot rotate the rod. Torque due to \[\text{F}=\text{1}00\text{sin3}0{}^\circ \]about fixed point O It is in clockwise direction. Torque due to \[\text{F}=\text{5}0\text{N}\] about fixed point It is also clockwise. \[\therefore \] Net torque acting on the rod = \[{{\tau }_{1}}+{{\tau }_{2}}=25+25=50N\,\,m;\] clockwise.