A positive charge of 9 µC exerts and attractive force of 1 N on an unknown charge 0.8 m away. The unknown charge in µC:

You hold a ruler that has a charge on its tip 3.80 cm above a small piece of tissue paper to see if it can be picked up. The ruler has –10.0 µC of charge. The tissue paper has 5.00 g of mass. What is the minimum charge required to pick up the tissue paper?

Electrons have a charge of q = -1.602 × 10-19 C. A student observes that a Styrofoam cup has a total charge of Q = -0.98 μC. Write an expression for the number of excess electrons N in the cup.

Sphere A has an excess of 5 x 1016 electrons and sphere B has an excess of 6 x 1017 electrons. The charge in Coulombs for sphere A is    and the charge in Coulombs for sphere B is    Word Bank: -.0032 C   -.004 C    -.012 C    -.14 C     -.096 C      -1.04 C     1.04 C     -0.30 C      -.008C    -0.12 C

A metal sphere has a charge of + 8.0 µC. (a.) How many electrons does it have? (b.) What is the net charge after 6.0 x 1013 electrons have been placed on it? Note: gnet = q1 + q2. Include the signs of the charges when solving for the net charge.

A 38-g ball of copper has a net charge of 1 μC. What fraction of the copper's electrons have been removed? (Each neutral copper atom has 29 protons and 29 electrons, and copper has an atomic mass of 63.5 a.m.u.)

Multiple Choice.

A metal sphere has a charge of +8.13μμC. What is the net charge after 5.80E+13 electrons have been added to it?

A dipole has a positive charge at x = 0.0 nm, y = 7.5 nm and a negative charge at x = 0.0 nm, y = -7.5 nm. The charges are unit charges. Find the electric field strength at x = 1.0 nm, y = 0.0 nm. (The value of k is 9.0 × 10' Nom?/C?.)

A thin conducting plate 1.0 m on the side is given a charge of −2.0 × 10−6 C . An electron is placed 1.0 cm above the center of the plate. What is the acceleration of the electron?