Ask Questions, Get Answers


A mass m is to be placed on the rod of length L and pivoted at its centre at a distance x from the left end of the rod so that the system shown in figure remains in equilibrium . Find x (Ignore the force between Q (beaneth q ) and 2q and the force between Q (beneath 2q) and q .

$(a)\;\large\frac{L}{2}\;(1-\large\frac{k\;q\;Q}{m\;g\;h^2})\qquad(b)\;\large\frac{L}{2}\;(1+\large\frac{k\;q\;Q}{m\;g\;h^2})\qquad(c)\;L\;(1-\large\frac{k\;q\;Q}{m\;g\;h^2})\qquad(d)\;\large\frac{L}{2}\;(1+\large\frac{k\;q\;Q}{2 m\;g\;h^2})$

1 Answer

Answer : (b)\; $\large\frac{L}{2}\;(1+\large\frac{k\;q\;Q}{m\;g\;h^2})$
Explanation :
F .B . D of rod
Since the system is in equilibrium the torque about the centre O should be zero . Therefore
$\large\frac{k\;q\;Q}{h^2}\;\large\frac{L}{2}-mg(\large\frac{L}{2}-x)-\large\frac{k\;2\;q\;Q\;L}{2 h^2 }=0$
answered Feb 18, 2014 by yamini.v
edited Feb 20, 2014 by yamini.v

Related questions