Classwork:
Name_______________________________
1. List all of the electrical forces within an atom. Which are attracting and which are repelling?
2. A very small positive charge (test charge) is located at the mid-point of the line joining two positively
charged spheres, the first of which has 3 times as much charge as the second.
(a) If the smaller sphere exerts a force of F on the test charge, what is the force the larger sphere
exerts on the test charge?
(b) What is the magnitude and direction of the two forces on the test charge?
3. A positive test charge is on the line joining two equally charged positive spheres and is located at a
point 1/3 of the distance between them.
(a) If the force exerted by the nearer sphere on the test charge is F, what is the force exerted by the
more distant sphere?
(b) What is the magnitude and direction of the two forces on the test charge?
4. A positive test charge is on the line joining two equally charged spheres and is located at a point 1/3 of
the distance between them. The closer sphere is negative and the farther sphere is positively
charged. What is the magnitude and direction of the two forces on the test charge?
5. What are the three ways to charge an object? Compare the charge on the object being charged and
the object doing the charging.
6. Where would the charges accumulate on a hollow metal sphere?
7. Why is it relatively safe to be in an airplane if it is hit by lightning?
8. What is the force between two equal positive charges of 4.0C that are 1.5m apart? ( = 10-6)
9. What is the force between a positive charge of 4.0C and a negative charge of 8.2C that are 0.50m
apart?
10. What is the force on a hydrogen atom? The electron and proton are approximately 5.3x10-11m apart
and the electron and proton have a charge of 1.6x10-19C.
11. What is the 30-30 rule for electrical lightning safety? Why is it important?
12. What is meant by "grounding" and why is it a safety issue?