College Physics 2 – Boot Camp Module 1 Name: Group Members:

College Physics 2 – Boot Camp
Module 1
Name: _________________________________________
Group Members: ________________________________
Electric Charge and Electric Fields
In the figure below two 9g balls are hanging by threads that can support masses of up to
10g. The threads are 10 cm long and are 10 cm appart.
10 cm
10 cm
For the next few questions you are not required to perform any calculations and you are
allowed to use the table above and the map below to subside your answers. Use
complete sentences to justify your answers.
1. Is it possible to break the trhread by electrically charging the balls Explain why or
why not
2. If charging the balls can break the thread would it make a difference if you are
charging the balls with like or unlike charges Explain your reasoning. If necessary draw
some diagrams to make your answer more clear.

College Physics 2 – Boot Camp
Module 1
3. Calculate the maximum horizontal force one can apply without breaking the thread.
4. Assume the force between the balls to be attractive. Calculate the maximum charge
that the balls can hold without breaking the thread.

College Physics 2 – Boot Camp
Module 1
5. Assume the force between the balls to be repulsive. Calculate the maximum charge
that the balls can hold without breaking the thread.
6. Do your answers to questions 4 and 5 agree with your answers to questions 1 and 2 If
not, analyze your answers and determine the source of the disagreement.

College Physics 2 – Boot Camp
Module 1
At each corner of a square of side l there are four point charges of magnitudes Q, and Q
(figure below).
l
Q -Q
l
l
-Q Q
l
1. Sketch the electric field lines due to this distribution of charge.
2. Indicate in your sketch where the magnitude of the field is the strongest. Justify
your answer.
3. Is there anyplace in the sketch of question 1 where the electric field is zero.
Justify your answer.

College Physics 2 – Boot Camp
Module 1
Now consider the following arrangement of the same charges.
l
Q -Q
l
l
Q -Q
l
4. Sketch the electric field lines due to this distribution of charge.
5. Indicate in your sketch where the magnitude of the field is the strongest. Justify
your answer.
6. Is there any place in the sketch of question 1 where the electric field is zero.
Justify your answer.

College Physics 2 – Boot Camp
Module 1
Consider two point charges of magnitudes 1C and 2C arranged as in the figure
below.
A
20 cm
10 cm
40 cm
B
1 C 2 C
20 cm
C
D
1) Determine the magnitude and direction of the electric field at point A, B, C, and D.
Show your work or justify your answer.

College Physics 2 – Boot Camp
Module 1
2) What will happen if you place a negative charge at point A Justify your answer.
3) What will happen if you place a positive charge at point A Justify your answer.
4) What will happen if you place a negative charge at point B Justify your answer.
5) What will happen if you place a positive charge at point B Justify your answer.