Lab’s goal To investigate the

Lab’s goal

To investigate the electrostatic interaction between variousobjects.

Theory

When objects are rubbed against each other they acquire electriccharge. Objects of the same electric charge repel and objects ofopposite charges attract.

Different materials have different “desire” for electrons; thisis called electronegativity.    Some materials willalways steal electrons from things they come in contact with;others are more willing to give up electrons.

Procedure

Activity 1: Determine how different objects interactthrough the electrostatic force.Top of Form

1. Cut 4 pieces about 10-cm-long scotch tape. Fold one end toprevent it from sticking.
2. Stick two pieces directly onto a smooth surface. Write “X” onthe folded end (both pieces are stuck on the table surface.)
3. Stick the third tape on the table as well. Write “B” on itsfolded end.
4. Stick the fourth tape (cut it less than 15 cm) on top of the”B” tape. Write “T” on its folded end.

Determine the interaction between the various scotch tapes, andvarious objects.

1) Pull the two “X” pieces off the top of the table. Bring themclose to each other.Do they repel or attract each other? __They repel eachother_____________________________________Does it matter which side faces which side? ­­­­­­­­­­­­­­­___Theside is irrelevant______________________

2) Pull the “T” and “B” pieces off the table together. Usingboth hands, separate the tapes abruptly. Bring them close to eachother.Do they repel or attract each other? ____They attract eachother___________________________________Does it matter which side faces which side? __The side isirrelevant______________________________

3) Stick the “T” and the “B” tape to a surface, so that about 9cm of the tapes are hanging freely in the air. Make sure the tapesare sufficiently far so that they do not interfere with each other.At any time if you notice the tapes are beginning to lose theircharge, you can recharge them by repeating the preliminaryset-up.

4) For each of the following objects, determine whether they arerepelled or attracted by tape “B” and tape “T”. Record your data inyour data table.

• Another “T” tape.
• Another “B” tape.
• “X” tape.
• Plastic rubbed with wool.
• Wood rubbed with wool.
• Glass rubbed with silk.
• A metal sphere.
• A paper sheet.
• Human hand

Record your data in the following table. Write down “attract” or”repel” according to your observations.

Results.

Arrange the objects in two categories according to theircharge.

What is the charge of the metal sphere?____________________________________

What is the charge of your hand?__________________________________________