Experiments with static electricity

1. On the Gizmo, click Show force vector for charge A and Show force vector for charge B. The forces on each charge are represented by the purple and green arrows. The charges of each particle, qA and qB, are shown below the particles. Check that each charge is set to 10.0 • 10−4 C.

a.Observe the arrows representing the Coulomb force between the charges. Do you think this represents an attractive or a repulsive force?
a. It shows a repulsive force.

b. Change the charge of particle A (qA) to -10.0. (To change qA, type a value in the field next to the slider and hit Enter.) You now have a positive and a negative charge (as in the "hair and balloon" experiment). What effect does this have on the arrows? Is this an attractive or repulsive force?
b. It shows a attracting force.

c. Change the charge of particle B to -10.0. What kind of force is experienced by two negative charges? You can model this by rubbing two balloons and slowly bringing them together.
c. It shows a repulsive force.

d. Change the charge of particle A back to +10.0. As a rule, what kind of force will result when charges are opposite? What kind of force will result when the particles have the same charge?
d. It's an attracting force again, so when two particles are the same charge they repel while if they are different it is the same.

2. Change the charge of particle A to 0.0. A particle with zero charge is neutral.

a. What happens to the force arrows?
a. The force arrows are not there anymore.

b. What is the force between a charged particle and a neutral particle? Try several values for particle B to see if this is always true. (Note: In reality, neutral objects are composed of charged particles. If you bring a charged object near a neutral object, the charged particles within the neutral object will rearrange themselves in a process called polarization. This results in an attractive force between the charged object and the neutral object that is not shown in the Gizmo.)
b. The relationship between neutral and a charged particles in the gizmo, is that there is no more attraction or repulsion. This is the case for both positive and negative charges. In real life though a process called polarization happens.

3. To see the magnitude of the Coulomb force, click Show vector notation for particle A and particle B. The magnitude of the force (in Newtons) is written |FA| or |FB|. Set each charge to 10.0 • 10−4. Click Show distance and Show grid, and drag the particles together until the distance between them is 30 m.

a. What is the Coulomb force on particle A?
a. 10n

b. What is the force on particle B?
b. 10n

c. Drag the particles around. Are the forces on particle A and B always equal to one another?
c.

4. Before altering the charges, write a hypothesis in your notes. What do you think the force will be if one of the charges is halved? When you have written your prediction, change the charge of particle A to 5.0 • 10−4 C and press Enter.

My hypothesis is that the coulomb force will be either a half or quarter less when one of the charges is halved.


a. What is the force on the particles now? Does this agree with your hypothesis?
a. The force on the particles is now 5, so the forces did half.


b. Change the charge of particle B to 5.0 • 10−4 C. What is the force now?
b. The force on the particles is now 2.5, so the forces did half.

c. Try several other combinations of charges. (Stick with whole numbers so it is easier to see the relationship.) What pattern do you see?
c. The fa is half way between the half of the smaller number and the average of the two original numbers.

d. Based on your observations, write an equation for Coulomb force when the distance is 30 m. If possible, compare and discuss your equation with your classmates.
d.

Static Electricity

Static electricity is the electricity formed when negatively and positively charged electrons coliseum and the friction that is created causes static electricity.

Static electricity is used in a number of things:

They are used in paper scanners. Paper scanners apply a negative or positive charge to the surface of where the paper will be applied, then when the paper is placed, light is shun through the paper, and where there is white the light is reflected and the charge on those areas leave, where the paper is not white, the charge stays. Then paper is placed om top of the plate or surface and the opposite charge of the plate charge is applied to the toner, and the toner applies ink where the opposite charge is. Then heat is used to stick the toner with the paper.



Static electricity is used in car spray paints, a charge is placed on the tip of the painter, and the opposite charge is placed on the car, so the paints land evenly on the car.



Static electricity is used in pollution control, where the dust particle in air are given charges and the collectors are given the opposite charge to attract the dust or dirt.

bibliography : "GCSE Science/Uses of Static Electricity - Wikibooks, Collection of Open-content Textbooks." Wikibooks. Wikimedia Foundation. Web. 27 May 2010. .

Circulatory System Quiz Questions

1. What is responsible for pumping blood through your body?

The heart (B).

2. The heart is a type of:

Muscle (A).

3. What makes up your body's circulatory system?

The heart, blood vessels and blood (C).

4. What does blood bring to the cells?

Oxygen and nutrients (A).

5. Where does blood become oxygenated?

In the Lungs (C).

6. What are three types of blood circulation in your body?

Coronary, pulmonary. and systematic. (B)

7. What is coronary circulation?

The circulation of blood in your heart (A)

8. Systematic circulation requires help from:

Arteries and Veins (C)

9. What is the superior vena cava?

A blood vessel (B).

10. What are arteries?

Blood vessels that move blood away from the heart (A).