Name:
Electrostatic Lab Simulation
Directions: Open the websites below in your web browser. (java/shockwave should be installed)
http://www2.wwnorton.com/college/physics/om/_content/_index/tutorials.shtml
Takes a while to download this! Then Select Chap. 22, Section 1: Electric ….
1. Draw the picture of a negative rod touching two connecting metal spheres (SHOW THE CHARGES!)
2. Why do electrons flow from the rod into the spheres and not the other
direction? (think about whether the rod or spheres are neutral to begin with)
3 .If the spheres were not conductive, but insulating draw a picture of where the extra electrons would go
Fast forward to section 4: Coulomb’s law
4. Draw a picture of 2 charged objects q1 and q2 at a distance “r” apart. Write down coulomb’s equation for force F.
5. Suppose someone calculates a force of -10 Newtons for two charges.
How can you tell if the charges are opposites or like charges?
(hint: think if the force is attractive or repulsive)
6. The equation for the force of attraction for gravity looks similar to coulomb’s law: Force= k*m1*m2 / r2.
the only difference is the constant k (smaller for gravity) and the use of masses (m 1,m2) instead of charges
Which force can only attract other objects?
7. Suppose the force between 2 objects is + 12 Newtons. If their distance apart was doubled,
what would be the new force and how do you do if it’s attractive or repulsive?
John Travoltage
http://phet.colorado.edu/new/simulations/sims.php?sim=John_Travoltage
…. Hit run now
8. Rub John’s foot on the carpet. Where does the charge come from?
9. Over time what happens to the excess charges in his body?
10. Ground John by touching his hand to the metal doorknob.
So when a person gets shocked, what happens? (which charge moves)
Balloon Phun: http://phet.colorado.edu/new/simulations/sims.php?sim=Balloons_and_Static_Electricity
………………..hit run now………..
11. Rub the balloon on the sweater. Why does the balloon want to keep close to the sweater?
12. Move the balloon near the wall. Draw a picture of the charges in the balloon & wall. What is the wall’s charge?
13. So when an object like the wall becomes polarized which charges move and why?
The Electroscope:
https://www.youtube.com/watch?v=Xu-3dkE3g4U
What is an electroscope? What is it used for? How does it work?
14. How do you charge an electroscope by contact (conduction)? – list the steps, draw a picture:
15. How do you charge an electroscope by induction? – list the steps, draw a picture showing the charges
Losing Charge: http://www.regentsprep.org/Regents/physics/phys03/atheft/default.htm
16. How does a charged object lose its charge to the atmosphere?
Lightning Phun: look at all three!
http://micro.magnet.fsu.edu/electromag/java/lightning/index.html
http://www.regentsprep.org/Regents/physics/phys03/alightnin/default.htm
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/estatics/u8l4e.html
17. What causes lightning? Draw charges in clouds & the ground:
18. Which charge moves toward earth?
Which charge move toward the clouds?
19. What causes the thunder associated with lightning?
20. What happens to the build-up of charges during each lightning strike?
21. Clouds and the ground make-up a capacitor- 2 charged areas with a dielectric material in between.
What is the dielectric material separating clouds and the ground? (rhymes with fair!)