Science 9 Lab: Investigating Static Electricity
Name:_______________________________________
25 Pts Total
1. Work with a group of 3. Pick up a pithball electroscope, a plastic rod and a piece of wool or fur. Rip
up a scrap of paper into small pieces. Rub the plastic rod with a wool cloth or fur. It charges best
when you rub it in the sme direction rather than back and forth. Now bring the charged rod to the
paper bits. Describe what happened (1 pt)
2. Sprinkle some salt grains on the counter. Rub the plastic rod with a wool cloth or fur and bring it
towards the salt grains. Describe what happens. (1 pt)
3. The plastic rod gets a negative charge when it is rubbed with a wool cloth or fur. In terms of
electrons (which have a negative charge), what must have happened to give the rod a negative
charge? (1 pt)
4. If the rod gets a negative charge when rubbed with a wool cloth, what charge does the wool cloth
get? Why? (1 pt)
5. Touch the pithball with your hand to ground it. After you have grounded the pithball, what charge
does it have? (1 pt)
6. Rub the plastic rod with a wool cloth or fur and bring it towards the pithball. Describe what happens
first and then what happens second after the ball touches the rod. What happened first as the plastic
rod APPROACHED the pithball was that:(1 pt)
What happened after second after the pith ball touched the rod was:
(1 pt)
7. Pick up a plastic bag and a glass rod. Again rip up a scrap paper into small bits or use the bits you
made from number 1 above. Rub the glass rod with the plastic bag and bring it towards the paper
bits. Describe what happened. (1 pt)
8. Again sprinkle some salt grains on the counter. Rub the glass rod with a plastic material and bring it
towards the salt grains. Describe what happens. (1 pt)
Science 9 Lab: Investigating Static Electricity
9. The glass rod gets a positive charge when it is rubbed with a plastic piece. In terms of electrons
(which have a negative charge), what must have happened to give the glass rod a positive charge? (1
pt)
10. If the rod gets a positive charge when rubbed with a plastic piece, what charge does the plastic piece
get? Why? (1 pt)
11. Touch the pithball with your hand to ground it. After you have grounded the pithball, what charge
does it have? (1 pt)
12. Rub the glass rod with a plastic piece and bring it towards the pithball. Describe what happens first
and then what happens second after the ball touches the glass rod. What happened first as the glass
rod approached the pithball was that:(1 pt)
What happened after second after the pith ball touched the glass rod was:
(1 pt)
13. Considering what the neutral pithball did as a charged rod was brought near to it (BEFORE it touched
it) , what force seems be between a neutral object (the pithball) and any charged object (negative or
positive rod)? (1 pt)
14. Let a small stream of water flow from the tap. What charge does the flowing water have? (1 pt)
15. Now rub your plastic rod with a wool cloth and bring the charged plastic rod towards the small
stream of water. Describe what happens. (1 pt)
16. What force was there between the flowing water and the charged rod? (1 pt)
17. Try charging the glass rod with a plastic piece and then bring it close to the small water stream.
Describe what happened. (1 pt)
Science 9 Lab: Investigating Static Electricity
18. What force was there between the positive glass rod and the neutral water stream? (1 pt)
19. Have one partner charge a glass rod by rubbing it with a plastic piece and a second partner charge the
plastic rod with a wool cloth or fur. A third partner can touch the pithball to ground it while the
other partners are charging the rods. Have the person with the charged glass rod touch the pithball a
few times. What charge does the pithball get when touched a few times by the charged glass rod? (1
pt)
20. Describe how the pithball that was touched by the charged glass rod moves when the charged glass
rod comes near. (1 pt)
21. Now have the person with the plastic rod bring it close to the charged pithball. Describe how the
pithball acts BEFORE it touches the plastic rod. (1 pt)
22. Is there a static charge law that explains why the ball moved as it did in number 20? The answer is
yes. Explain what this law says. (1 pt)
23. State the three laws of static electricity about forces of attraction and repulsion. (1 pt)