Problem 3. A small, charged pith ball is suspended 6 mm above a second charged ball resting on an insulated surface. If the charge of the lower ball is +25.0 SC and it has a mass of 0.385 g, what charge must be placed on the upper ball to lift the lower ball?

A sphere has a net charge of 8.05 nC, and a negatively charged rod has a charge of 6.03 nC. The sphere and rod undergo a process such that 5.00 109 electrons are transferred from the rod to the sphere. What are the charges of the sphere and the rod after this process?

An object has a charge of 35 nC. How many excess protons does it have?

A person is placed in a large, hollow, metallic sphere that is insulated from ground, (a) If a large charge is placed on the sphere, will the person be harmed upon touching the inside of the sphere? (b) Explain what will happen if the person also has an initial charge whose sign is opposite that of the charge on the sphere.

Two small, identical metal balls with charges 5.0 C and 15.0 C are held in place 1.0 m apart. In an experiment, they are connected for a short time by a conducting wire. a. What will be the charge on each ball after this experiment? b. By what factor will the magnitude of the electrostatic force on either ball change after this experiment is performed?

Assume the charged objects in Figure OQ23.10 are fixed. Notice that there is no sight line from the location of q2 to the location of q1. If you were at q1, you would be unable to see q2 because it is behind q3. How would you calculate the electric force exerted on the object with charge q1? (a) Find only the force exerted by q2 on charge q1. (b) Find only the force exerted by q3 an charge q1. (c) Add the force that q2 would exert by itself on charge q1 to the force that q3 would exert by itself on charge q1. (d) Add the force that q3 would exert by itself to a certain fraction of the force that q2 would exert by itself. (e) There is no definite way to find the force on charge q1.

Two particles with charges q1 and q2 are separated by a distance d, and each exerts an electric force on the other with magnitude FE. a. In terms of these quantities, what separation distance would cause the magnitude of the electric force to be halved? b. In terms of these quantities, what separation distance would cause the magnitude of the electric force to be doubled?

A 50.0-g ball of copper has a net charge of 2.00C. What fraction of the copper's electrons has removed? (Each copper atom has 29 protons, and copper has an atomic mass of 63.3.)

Common static electricity involves charges ranging from nanocoulombs to microcoulombs. (a) How many electrons are needed to form a charge of 2.00 nC (b) How many electrons must be removed from a neutral object to leave a net charge of 0.500 C ?

Three charged particles are located at the corners of an equilateral triangle as shown in Figure P19.9. Calculate the total electric force on the 7.00-C charge.