# More Coulomb's Law Problems

1. A point charge of +0.6uC is separated by a distance of 4cm from a point charge of -18.0uC.  What is the force on each charge? (-60.7N)
2. A point charge of +2.5uC is separated by a distance of 12cm from a point charge of +3.0uC.  What is the force on each charge? (4.7N)
3. How many excess electrons are in a -2.0uC charge? (1.25E13 electrons)
4. A balloon rubbed against denim gains a charge of -8.0uC.  What is the electric force between the balloon and the denim when the two are separated by a distance of 5.0cm? (-230N)
5. Two identical conducting spheres are placed with their centers 0.30m apart.  One is given a charge of +12E-9C and the other is given a charge of -18E-9C.
1. Find the electric force exerted on one sphere by the other. (-2.1E-5N)
2. The spheres are connected by a conducting wire.  After equilibrium has occurred, find the electric force between the two spheres. (8.99E-7)
6. A small cork with an excess charge of +6.0uC is placed 0.12m from another cork, which carries a charge of -4.3uC.
1. What is the magnitude of the electric force between the corks? (16.1N)
2. Is this force attractive or repulsive? (attractive)
3. How many excess electrons are on the negative cork? (2.69E13 electrons)
4. How many electrons has the positive cork lost? (3.7E13 electrons)
7. Two electrostatic point charges of +60.0uC and +50.0uC exert a repulsive force on each other of 175N.  What is the distance between the two charges? (0.39m)