Balloon and Static electricity Teacher activity (activity 8 question 1)

PHet Electricity Simulations Analysis Worksheet

Name: Leah

Balloons and Static Electricity

to the website: https://phet.colorado.edu/en/simulation/balloons-and-static-electricity and click on the “Play” symbol to open the simulation.

1.    Count the number of positive and negative charges on each object in the simulation and determine the overall charge of each object.

	+ Charges	-      Charges	Overall Charge
Sweater	57	57	0
Balloon	4	4	0
Wall	52	52	0

2.    Click on the balloon and drag it over and rub the balloon against the wall.  Describe what, if anything, happens to the balloon/wall.  Pull the balloon slightly away from the wall and release it, does anything happen?

When rubbed against the wall nothing happened. When pulled away from the wall and released nothing changed with the balloon.

3.    Now drag the balloon over the sweater and rub it against the sweater.  Describe what, if anything, happens to the balloon/sweater.

All of the negative charges moved to the balloon and the balloon stuck to the sweater

4.    Count the number of positive and negative charges on each object in the simulation and determine the overall charge. (It might be easier to select “show charge differences” and count how the charges have changed and use your numbers above to answer.)

	+ Charges	-      Charges	Overall Charge
Sweater	57	0	positve
Balloon	4	57	negative
Wall	0	0	No charge

5.    Pull the balloon back toward the middle of the simulation and let it go, describe what happens?  How can you explain this occurrence?

The balloon moves back to the sweater. This happens because the balloon is negatively charged and the sweater is positively charged. Opposites attract each other.

6.    Drag the balloon over to the wall.  As you bring the balloon near the wall, what happens within the wall?  Why do you think this happens?

The balloon sticks to the wall but all negative charges move away. The negative charges are trying to balance out to the wall and do not require extra charges.

7.    Hold the balloon just away from the wall and release it.  What happens?  Why do you think this happens?

The balloon moves back to the wall to balance out its charge.

8.    Hold the balloon a little further from the wall and release it, keep repeating this moving the balloon a little bit further from the wall each time until the balloon stops being attracted to the wall.  What eventually happened?  Is the balloon more attracted to the sweater or the wall?  Why?

It took less than half the distance for the balloon to return to the sweater because it has such a strong positive charge unlike the wall that has no charge. The balloon is more attracted to the sweater.

Click “Reset Balloon” then click on the picture with two balloons.  Lastly click on “remove wall” to remove the wall.

9.    Determine the number of positive charges, negative charges and the overall charge of each object. (Sweater number should not have changed.)

	+ Charges	-      Charges	Overall Charge
Sweater	57	57	No charge
Green Balloon	4	4	No charge
Yellow Balloon	4	4	No charge

10. Take the green balloon and rub it gently against the sweater.  Then determine the new charges.

	+ Charges	-      Charges	Overall Charge
Sweater	57	49	postive
Green Balloon	4	12	negative
Yellow Balloon	4	4	No charge

11.  Drag the green balloon over to the yellow balloon, does it have any effect on the yellow balloon?  Why or why not?

It has no effect to the yellow balloon because the yellow balloon has no charge

12.  Release the green balloon, what happens?  Why?

The green balloon moves to the sweater because it has a positive charge

13.  Now drag the yellow balloon and rub it against the sweater.  Determine the new charges.

	+ Charges	-      Charges	Overall Charge
Sweater	57	39	postive
Green Balloon	4	12	negative
Yellow Balloon	4	14	negative

14. Pull the green balloon off the sweater and put it all the way across the room.  Quickly grab the yellow balloon and bring it near the green balloon?  What happens when the balloons are brought together?  Why does this happen?

The green balloon moves away from the yellow balloon and quickly moves back to the sweater. The yellow balloon sinks down and moves back to the sweater. Both are negatively charge and will not attract one another. When brought together they move apart.

15. Try to find a way to get the 2 balloons to stick to each other. 

Both will stick together when they are placed on the sweater next to eachother

16. What would you need to do in order to get the balloons to stick together?  After completing this activity is it possible to do that?  Why or why not?

You would need more positive charges on one balloon to have them stick together. With this simulation it is not possible to do that.

Analysis

17.  When an object becomes charged which charge is transferred between the objects?

Positive and negative ions

18.   How does an object become positively charged?

All the negative or most are removed

19.   How does an object become negatively charged?

All the positive ions or most are removed

20.  In order to repel each other two objects must have  the same charge(s).

21.   In order to attract each other two objects must have opposite charge(s).

22.  When the balloon was brought near the wall, the wall technically stayed neutral, but the balloon was still attracted to the wall.  How can this be explained?

The balloon was attracting the positive ions but the wall was not completely positive.

Part B: John Travoltage!

Go to the following: http://phet.colorado.edu/en/simulation/john-travoltage and click Play!  (sound on makes it more fun!)

1)     Click on John Travoltage’s arm and move his finger by the doorknob.  What happens?

Nothing happens

2)     Move his finger away from the doorknob and rub John Travoltage’s FOOT across the carpet. Describe what happens!

Negative ions move up his foot and to his finger.

3)     Move his finger toward the doorknob again.  Describe what happens this time.  Why does that happen?

He is shocked. The positive charge from the doorknob has extra ions that want to move to his hand and it shocks him.

4)     Move his finger away again and drag his foot across the carpet multiple times.  Then bring his hand toward the doorknob again.  What do you notice about the distance between his finger and the doorknob this time compared to the first time?  Why do you think its changed.

His hand is further away but the shock gets longer. He is still shocked because the number of negative ions increased greatly and still want to “jump” to the source.

5)     Before John Travoltage approaches the doorknob is the doorknob charged or neutral?  What evidence do you have to support your claim?

The door knob is positively charged because it is made of metal. Metal is postivly charged. 

6)     a) Why does carpet tend to produce differences in static electricity more than hardwood or tile floors (think!)?

The carpet is not as smooth and can build up negative charges from movement.

b) Why do you sometimes feel a shock when you touch metallic objects (like the doorknob)?

Metal is positively charged and we collect more negative ions.

7)     Why doesn’t John Travoltage get a shock if he touches the doorknob without rubbing his foot on the carpet?

He is neutrally charged

8)     Charge John Travoltage up a lot and observe which direction the spark travels when John Travoltage’s finger comes close to the metal doorknob.

a)     Draw a diagram of his finger and the doorknob below.

b)     Label the CHARGES (positive, negative, neutral) of both objects and show the direction the spark is traveling!