Wednesday, June 2, 2010
Experiments with Static Electricity
a. Observe the arrows representing the Coulomb force between the charges. Do you think this represents an attractive or a repulsive force?
Ans. 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?
Ans. Attractive 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.
Ans. It is a repulsive force because they are not opposites
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?
Ans. The charges are opposite so they will attract
2. Change the charge of particle A to 0.0. A particle with zero charge is neutral.
a. What happens to the force arrows?
Ans. The arrows are not there any more
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 calledpolarization. This results in an attractive force between the charged object and the neutral object that is not shown in the Gizmo.)
Ans. There is no force
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?
Ans. 10n
b. What is the force on particle B?
Ans. 10n
c. Drag the particles around. Are the forces on particle A and B always equal to one another?
Ans. Yes
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.
a. What is the force on the particles now? Does this agree with your hypothesis?
Ans. The force has decreased to 2.81 and that doesn’t agree with my hypothesis
b. Change the charge of particle B to 5.0 • 10−4 C. What is the force now?
Ans. It has decreased to 1.41
c. Try several other combinations of charges. (Stick with whole numbers so it is easier to see the relationship.) What pattern do you see?
Ans. The larger the charges, the larger the force
Sunday, May 30, 2010
Pollution Control Static electricity is used in pollution control by applying a static charge to dirt particles in the air and then collecting those charged particles on a plate or collector of the opposite electrical charge.
Spray painting car parts By connecting the spray nozzle to a negative electrode, it is possible to charge each droplet of paint. If the car part is then given the opposite charge, the paint droplets will be attracted to the car body part.
Photocopy Copy machines use static to make ink get attracted to the areas where we need the information copied.
Bibliography:
• "GCSE Science/Uses of Static Electricity - Wikibooks, Collection of Open-content Textbooks."Wikibooks. Web. 27 May 2010.
• "Uses of Static Electricity." HubPages. Web. 27 May 2010.
Saturday, May 29, 2010
Static electricity
Bending water is an example of static electricity you can use a rod or a ruler and rub it against your hair or a cloth so electons can be moved and when you put the rod near water it bends.
Lightening is an example of static discharge, it is unclear why that happens but the initial charge seperation is thought to be associated with contact between ice particles within storm clouds.
This is another example showing a girl touching a static electricity generator which is moving electrons up to the girls hair and then the hair separates.
Tuesday, May 4, 2010
Muscles Questions
Ans2.The other muscle relaxes
Ans3.When the model is streached it is accurate
Ans4.When the model is relaxed it is inaccurate
Ans5.Hinge joint
Friday, April 23, 2010
Circulatory System Quiz
1b. Left atrium receives blood returning from the lungs
1c. Left ventricle pumps blood to the body
1d.Right ventricle pumps blood to the lungs
3a. Inferior vena cava carries blood from the right atrium
3b. Superior vena cava carries blood from the right atrium
3c. Pulmonary artery carries blood from the right ventricle to the lungs
3d. Aorta carries blood from the left ventricle to the body
4a. Systole is when blood is pushed out of the heart into the arteries
4b. Diastole is when blood fills ventricles
5. The valves between the atria and ventricles are called the Atrioventricular valves
6a. Systemic circulation is the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart.
6b. Pulmonary circulation is the portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.
7a. Arteries are blood vessels that carry blood away from the heart
7b. Veins are blood vessels that carry blood towards the heart
7c. Arterioles are small blood vessels that extend and branch out from an artery and lead to capillaries
7d. Venules are small blood vessels that allow deoxygenated blood to return from the capillary beds to the larger blood vessels called veins
7e. Capillaries are blood vessels that connect the arteries and veins
8. Cardiac arteries supply the heart tissue with oxygen
9. Hepatic portal vein carries blood from the small intestine to the liver
10.
11. Artery
12. Vena Cava, Right Ventricle, Right Atrium, Pulmonary Veins, Pulmonary Artery, Lungs,
, Pulmonary Veins , Left Atrium , Left Ventricle ,Aortic Valve , Aorta
14.
15. The aorta divides the pulmonary arteries
Wednesday, April 21, 2010
Lungs, Smoking and Asthma
Lungs
The lungs are a part of the respiratory system they are soft and spongy and cone shaped, they are two separated sacs or bags which take in air when you inhale, alveoli's are small sacs located in the lungs there are millions of them, and they take in oxygen and remove carbon dioxide when you breathe. Lungs decrease in size when you exhale because the diaphragm flattens and when you inhale the diaphragm contracts which gives more space for the lungs to expand as they fill up with air.
Smoking
Smoking destroys your lungs, cigarettes are full of chemicals that hurt your body, and they hurt your lungs with three types of grot nicotine, tar and carbon monoxide. Smoking can give you lung cancer, makes you lose your sense of smell, heart disease, shortness of breath known as emphysema, stomach cancer, mouth and throat cancer, stained teeth and bad breath, and more coughs and colds.
Asthma
Asthma is a common condition in the lungs; people who have asthma can experience coughing, shortness of breath, and tightness in the chest. People who have asthma get asthma attacks because of impure or unclean air which makes there trachea swell and that makes breathing harder so they use their inhalers to expand the trachea to breath easily, attacks can also be triggered by exercise, food allergies, weather, or even emotions sometimes.