PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Torque and Rotational Dynamics · Torque and Rotational Dynamics
Problem
A long non-conducting, massless rod of length l is pivoted at its centre and balanced with a weight w at a distance x from the left end. Small conducting spheres with positive charges q and 2q are attached to its left and right ends, respectively. A fixed sphere with positive charge q is a distance h directly beneath each attached sphere. Ignore the force between diagonally separated spheres and the force between the two fixed spheres.
(1) Find the distance x for which the rod is horizontal and balanced.
(2) What value should h have so that the rod exerts no vertical force on the bearing when the rod is horizontal and balanced?