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Physics Unit 7 Worksheet 1: Electric Charge and Electric Force
Name: _______________
1. On two occasions, the following charge interactions
between balloons A, B and C are observed. In each case, it is
known that balloon B is charged negatively. Based on these
observations, what can you conclusively confirm about the
charge on balloon A and C for each case?
Case 1 Balloon A: Case 2 Balloon A:
Case 1 Balloon C: Case 2 Balloon C:
2. Upon entering the room, you observe two balloons suspended from the ceiling. You
notice that instead of hanging straight down vertically, the balloons seems to be repelling
each other. You can conclusively say: (choose an option)
a. both balloons have a negative charge.
b. both balloons have a positive charge.
c. one balloon is charge positively and the other negatively.
d. both balloons are charged with the same type of charge.
3. Jean Yuss is investigating the charge on
several objects and makes the following findings.
Jean knows that object A is negatively charged
and object B is electrically neutral. What can
Jean Yuss definitively conclude about the charge on objects C, D, E, and F?
C: _____________ D: _____________ E: _____________ F: _____________
4. Two objects are charged as shown at the right. Object X will attract/repel/not affect object Y.
5. Two objects are shown at the left. One is neutral and the other is negative.
Object X will attract/repel/not affect object Y.
6. Balloons X , Y and Z are suspended from strings as shown at the right.
Negatively charged balloon X attracts balloon Y and balloon Y attracts
balloon Z. Balloon Z ____. Choose all that apply.
a. may be positively charged b. may be negatively charged
c. may be neutral d. must be positively charged
e. must be negatively charged f. must be neutral
7. During a physics lab, a plastic strip was rubbed with cotton and became positively charged. The correct
explanation for why the plastic strip becomes positively charged is that ...
a. the plastic strip acquired extra protons from the cotton.
b. the plastic strip acquired extra protons during the charging process.
c. protons were created as the result of the charging process.
d. the plastic strip lost electrons to the cotton during the charging process.
8. Plastic Wrap has a larger electron affinity than Nylon. If Nylon is rubbed against Plastic Wrap, which would end up
with the excess negative charge?
9. Which statement best explains why a rubber rod becomes negatively charged when rubbed with fur?
a. The rubber that the rod is made of is a better insulator than fur.
b. The fur is a better insulator than the rubber.
c. Molecules in the rubber rod have a stronger attraction for electrons than the molecules in the fur.
d. Molecules in the fur have a stronger attraction for electrons than the molecules in the rubber rod.
Object C
Object D
Object E
Object F
attracts B
repels C
attracts D
repels F
attracts A
