(III) Two positive charges are affixed rigidly to the x axis, one at and the other at A third charge of mass m, which is constrained to move only along the x axis, is displaced from the origin by a small distance and then released from rest. (a) Show that (to a good approxima- tion) will execute simple harmonic motion and deter- mine an expression for its oscillation period T. (b) If these three charges are each singly ionized sodium atoms at the equilibrium spacing typical of the atomic spacing in a solid, find T in picoseconds.

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative