Part 1: We consider a homogenous bar with mass m=0.1kg and length L can rotate around a fixed axis (A) passed from its extremity O. the other extremity is attached to the spring with constant K = 20 N/m. In the equilibrium state the vertical line and the axis (A) formed the angle a = 30° (look at the figure). 1- Count all forces applied to the bar? 2- Write two conditions to have the equilibrium state? 3- Find the expression of spring tension T in function of m,g,a. Then Calculate its value? 4- Deduce the Spring elongation? 5-Draw the figure and represent in it all external forces without scale?
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