Two spheres are mounted on identical horizontal springs and rest on a frictionless table, as in the drawing. When the spheres are uncharged, the spacing between them is 0.05 m, and the springs are unstrained. When each sphere has a charge of +1.6 £gC, the spacing doubles. Assuming that the spheres have a negligible diameter, determine the spring constant of the springs?

Question

Two spheres are mounted on identical horizontal springs and rest on a frictionless table, as in the drawing. When the spheres are uncharged, the spacing between them is 0.05 m, and the springs are unstrained. When each sphere has a charge of +1.6 £gC, the spacing doubles. Assuming that the spheres have a negligible diameter, determine the spring constant of the springs?
3. Three charges are fixed to an x, y coordinate system. A charge of +18 £gC is on the y axis at y = +3.0 m. A charge of -12 £gC is at the origin. Last, a charge of +45 £gC is on the x axis at x = +3.0 m. Determine the magnitude and direction of the net electrostatic force on the charge at x = +3.0 m. Specify the direction relative to the ¡Vx axis.
4. A particle has a charge of +1.5 £gC and moves from point A to point B, a distance of 0.20 m. The particle experiences a constant electric force, and its motion is along the line of action of the force. The difference between the particle¡¦s electric potential energy at A and B is EPEA - EPEB = +9.0ƒù10-4 J.
a. Find