A 26.3-g mass is suspended 4.35 cm above a nonconducting flat plate, directly above an embedded charge of q.  a) If the mass has the same charge, q, how much must q be so that the mass levitates (just floats, neither rising nor falling)? b) If the charge q is produced by adding electrons to the mass, by how much will the mass be chan

Two particles, one with charge -7.13 µC and one with charge 3.55 µC, are 6.59 cm apart. What is the magnitude of the force that one particle exerts on the other? force: TOOLS 93=== Two ne x10 entical positive charge qs, are placed the same 6.59 cm apart, and the force between them is measured to be the same as that between the original particles. What is q? N HC

Two small spheres each have a mass m of 0.700 g and are suspended as pendulums by light insulating strings from a common point, as shown in the figure below. The spheres are given the same electric charge, and the two come to equilibrium when each string is at an angle of 0= 6.00%; with the vertical. m OK 410 m 1) If each string is 1.00 m long, what is the magnitude of the charge on each sphere? (Express your answer to three significant figures.) x 10-⁹ C

1) a. You hold a ruler that has a charge on its tip 4.00 cm above a small piece of tissue paper to see if it can be picked up. The ruler has -14.0 µC of charge. The tissue has 1.00 g of mass. What is the minimum charge required to pick up the tissue paper? b. A 50.2 g ball of copper has a net charge of 2.2 pC. What fraction of the copper's electrons have been removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.5.) c. How many coulombs of positive charge are there in 1.36 kg of plutonium, given that its atomic mass is 244 and each plutonium atom has 94 protons?