Name: ______Block: ______
Science 9 – Ch. 9 Static Electricity
9.5 Application of Static Electricity
Before electricity was known, people were aware of shocks from ______. Ancient Egyptian referred to these fish as protector of all fish. They also knew that these shocks created this numbing effect and could travel along conducting objects. Patients suffering from ______(red swollen joint) and ______were advised to touch electric fish to cure them.
A. Lightning
______
Lightning can strike the same spot twice
A tall building is the most likely place to be hit by building
______are placed so that they get hit and not the building
· Clouds contain millions of ______that ______as they rise and fall.
· Collisions cause ______to ______à ______of cloud becomes ______and ______becomes ______
· Air around cloud provides a brief pathway for ______to flow from the ______to the ______
o Electron flow excites surrounding air and light is emitted à ______
o ______quickly and send out a shock wave à ______
Airplane / Car:
When a conductor becomes ______, the charge tends to remain on the surface of the object. If ______ hits a metal car, the charge will stay on the outside of the car. A person in the car will be ______. However, if the person touches the metal body of the car, he/she will receive a ______
B. Laser Printers How static electricity is used in photocopiers
1. A selenium coated drum is rubbed onto a brush. The selenium coated drum is positively charged.
2. The light is shined onto the page that is to be copied. Being reflected through several mirrors, it is finally reflected onto the selenium coated drum.
3. The selenium becomes conductive as the light hits it. The charges get rearranged until the charge is neutral. There is only positive charge on the parts of the drum where there was no light- the silhouette of the print on the page being photocopied.
4. There is a brush that picks up negatively charged toner (a fine black powder) made of plastic beads and carbon particles. When the brush rolls onto the selenium, the negative toner is attracted to the positive charge left on the drum.
5. Positively charged paper picks up the toner from underneath the selenium coated drum.
6. The paper is finally heated to melt and seal the toner onto the paper.
C. Fabric Softener Sheets & Static Cling
D. Electrostatic Precipitators
“Danger of static electricity while refueling”
· If a person carries a static charge, a spark will occur when near gasoline fumes which can produce an explosion.
· How can this be avoided?
o When you first grab the fuel nozzle, you will ______your static charge When fueling, make sure that the nozzle is inserted completely into the tank to minimize the possibility of fumes escaping
o Do not go back into your car while fueling – this leads to ______and can generate static charge
If you go back into your car and then touch/remove the nozzle, the charge you carry will cause an explosion
9.5 CYU’s #3-8, 12
9.5 Application of Static Electricity assignment
1. Lightning
a. Draw a picture of a couple of clouds above the ground.
b. How does the cloud get charged? ______
______
c. Draw in + and – signs to show how the charge is separated in a cloud.
d. Draw in lightning bolts to show two ways the charge can be neutralized.
2. Laser Printers
a. What part of the printer becomes positively charged?______
b. How is the image made?______
3. Static Cling
a. What are the chemicals in fabric softeners and what do they do?
______
______
4. Electrostatic Precipitators
a. Using pictures or point form, describe how solid pollution is removed in an
electrostatic precipitator.