Question

Experiment 1: Exploring Charge with Scotch® Tape
In this experiment, you will observe the behavior of charged objects using pieces of Scotch® tape.

Materials
Scotch® Tape
Ruler
*Pen     
*Flat Work Surface

  

Procedure
Part 1
1.   Use the ruler to measure a piece of tape that is 10 cm long.
2.   Tear the tape to remove the 10 cm piece from the roll.
3.   Create a “handle” on one side of the piece of tape by folding down the piece of tape 1 cm from the end, leaving a 9 cm sticky piece with a 1 cm handle.
4.   Stick the entire sticky surface of the tape to a table top, counter top, or another flat surface.
5.   Repeat Steps 1 – 4 with a second 10 cm piece of tape. Stick the second piece of tape at least 15 cm away from the first piece on the same surface.
6.   Quickly pull off both strips of tape from the surface and ensure that the pieces do not touch.
7.   Carefully bring the non-sticky sides of the tape together and record observations about the behavior of the pieces in Table 1.
8.   Discard the tape.
Part 2
1.   Use the ruler to measure a piece of tape that is 10 cm long.
2.   Tear the tape to remove the 10 cm piece from the roll.
3.   Create a “handle” on one side of the piece of tape by folding down 1 cm of tape from one end.
4.   Stick the entire sticky surface of the tape to a table top, counter top, or another flat surface.
5.   Use a pen and write “B1” on the tape. “B” stands for bottom.
6.   Repeat Steps 1 – 4 with a second 10 cm piece of tape. This time, press the second strip of tape on top of the one labeled “B1”.
7.   Use the pen to label the top piece with a “T1”. “T” stands for top.
8.   Create a second pair of pieces of tape by repeating Steps 1 – 7. This time, label the bottom piece “B2” and the top piece “T2”.
9.   Use the T1 handle to quickly pull off T1 strip of tape from the flat surface.
10.   Use the B1 handle to peel off the bottom strip from the flat surface. Keep both B1 and T1 pieces away from each other.
11.   Bring the non-sticky sides of B1 and T1 together and record observations about the behavior of the pieces in Table 1.
12.   Set the pieces of tape, non-sticky side down, on the table approximately 15 cm away from each other. Do not stick them back on the table!
13.   Repeat Steps 9 - 12 for B2 and T2.
14.   Carefully bring the non-sticky sides of piece “T1” and “B2”. Record observations about the behavior of the pieces in Table 1.
15.   Set them back down, non-sticky side down.
16.   Repeat Steps 14 - 15 for “T1” and “T2”. Record your observations in Table 1.
17.   Repeat Steps 14 - 15 for “B1” and “B2”. Record your observations in Table 1.
18.   Repeat Steps 14 and 15 for “T1” and the hair on your leg or arm. Record your observations in Table 1.
19.   Repeat Steps 14 and 15 for “B1” and the hair on your leg or arm. Record your observations in Table 1.

Table 1: Electric Charge Observations

procedure	interacting pieces	observation
Part 1	Two pieces on table
Part 2	T1 / B1
	T2 / B2
	T1 / B2
	T2 / B1
	B1 / B2
	T1 / Arm Hair
	B1 / Arm Hair

***The observation is filled.

Post-Lab Questions

1.   Describe the interaction between the top and bottom strips as they relate to electric charge. Did the behavior of the pieces change when the tape was from different sets?

2.   Describe the interaction between two top and two bottom pieces of tape as they relate to electric charge. Is this consistent with the existence of only two types of charge? Use your results to support your answer.

3.   Did the top tape attract your arm hair? Did the bottom tape attract your arm hair? Usually arm hair is neutral; it has equal number positive and negative charges. Use this information to explain your results.

4.   Which pieces of tape are positively charged? Which pieces of tape are negatively charged? Explain your reasoning.

5.   Use your data to create a rule describing how like charges, opposite charges, and neutral bodies interact.

6.   What do you observe about the force of attraction or repulsion when the pieces of tape are closer together and farther apart? Does this change happen gradually or quickly?

Answer 1

1. I observed that the top piece of each pair attract the bottom piece of each pair and both top pieces(or bottom pieces) of each pair repels.

2.When the tape is pulled apart, the original number of movable charged particles (electrons) are unevenly distributed between the pieces of tape. No net charge is created in the process. If the pieces were originally neutral, the tape with more electrons will be negatively charged and the tape with fewer will be positively charged. The magnitude of the positive and negative charge will be the same. Therefore the sum of the final charges will equal the initial charge (in this case neutral).

3.yes, both the taps attract my arm hair. As hair is neutral when it comes in the field of electrostatic charge a dipole is induced in hair as a result ion dipole attraction forces takes place.

4.Under the "electron fluid" model electrons flow from one piece of tape to the other while they are being pulled apart. The tape with more "electron fluid" at the end is negatively charged. The piece that lost the "fluid" is positively charged.

5. Like charges repel each other, opposite charges attract each other and when a neutral body comes in interact with a charged body ion induced attraction forces takes place.

6. The forces of attraction or repulsion gets weaker with increasing the distance between the pieces.