Experiments with Static Electricity

Interactions between Charged Particles

In this activity, you will use the Gizmo™ to explore the relationships between charge and force.

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, q_A and q_B, are shown below the particles. Check that each charge is set to 10.0 • 10⁻⁴ C.
   1. Observe the arrows representing the Coulomb force between the charges. Do you think this represents an attractive or a repulsive force?
   2. Change the charge of particle A (q_A) to -10.0. (To change q_A, 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?
   3. 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.
   4. 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?
2. Change the charge of particle A to 0.0. A particle with zero charge is neutral.
   1. What happens to the force arrows?
   2. 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.)
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 |F_A| or |F_B|. 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.
   1. What is the Coulomb force on particle A?
   2. What is the force on particle B?
   3. Drag the particles around. Are the forces on particle A and B always equal to one another?
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.
   1. What is the force on the particles now? Does this agree with your hypothesis?
   2. Change the charge of particle B to 5.0 • 10⁻⁴ C. What is the force now?
   3. Try several other combinations of charges. (Stick with whole numbers so it is easier to see the relationship.) What pattern do you see?
   4. 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.

Uses and Examples of Static Electricity

Static electricity is created when two materials rub together and electrons are transported from one surface to the other. This causes one surface to take on the role of a negatively charged, which has gained electrons from the other surface. And the surface that has lost electrons to the the negatively charged surface, is positively charged due to lack of electrons. The both attract to each other, because + and - are always attracted to each other. Static Electricity is basically energy that doesn't have its electrons moving.

How air travels through the respiratory system(nose to lungs):

pharynx- larynx-trachea-bronchi-bronchioles-alveoli

Which is the odd one out:

esophagus because its part of the digestive system

Dust particles that are in the air in the respiratory system get out via the nasal cavities hairs-cilia

Smallest respiratory passageway: Broncioles

Separates mouth from nose: Palate

Windpipe: Trachea

Where gas exchange takes place: Alveoli

Stops food going the wrong way: Epiglottis

Air/food pass through: pharynx

Movement of air out of lungs: expiration

Main muscle involved in inspiration: Diaphragm

Membranes that cover the lungs and line the pleural cavity: Pleura

The volume of air inhaledor exhaled at each normal breath: Tidal Volume

Unhealthy and Healthy foods

Unhealthy foods usually contain large amounts of Sodium and Fat (of which is also partially saturated). Foods with empty calories have no vitamins or minerals, or fat, just plain calories, such as the cheetos used in the class for the experiment.

Name all the parts of the digestive system and their functions

Name all the parts of the digestive system and their functions:

Mouth

- Chemical Digestion [Carbohydrates] -> Enzymes

- Saliva Slimes your food so it can easily slide down your esophagus

- Mechanical (Physical) Digestion [Chewing food breaking it into smaller pieces]

Esophagus

- Squeezes the food down to the stomach

Stomach

- Stores Food

- Mixes food (mechanical digestion)

- Makes acid-> in order to breakdown protein

Enzyme pepsin-> breaks down protein ph-2 in your stomach when you get food inside

Small Intestine

- Fats (lipids), carbohydrates, proteins are all finished getting digested

- All of these are absorbed into your blood from your small intestine

Pancreas

- Makes all the important enzymes that go to digest fats, carbohydrates, proteins

Makes insulin in order for your body cells to suck up

Sugar (glucose)

Liver

- Makes bile which is stored in your gall bladder and sent to your small intestine to help digest fat.

- Filters blood from small intestine

- Store sugar, so it can be released

Large Intestine

- Stores undigested food

- Stores water

What is My MYP Grade

My MYP grade for the 2nd term in eighth grade, is 6. I was on the borderline between a 6 and a 7, and got a 6, because I got 32. The science areas I need to improve on are criterion c, meaning I should prepare more for tests, to push myself to a 7 in criterion c. Criterion F should also be worked on, as 4 was the latest grade for that criterion out of 6

Digestive System

Mouth:

-Teeth breakdown food physically for easy digestion.

-Produces Saliva so the food can easily slide through esaphagus

-Produces enzymes (acid like chemical) which help break down food (chemical digestion).

Blog Title: Newton's Three Laws of Motion.

Newton's first law:

Things in motion will keep going until a force such as friction will slow them down until they slow down

Example: If a car was going along a road and its engine was off, the car will eventually stop because of the friction between the road and tyres. If a rocket was pushed into outer space it'll keep going because no force is there to stop it.

Newtons second law:

Things with a heavier mass will accelerate slower than a thing with a lighter mass.

Example: If two skateboards are pushed by the same time and one of them has a load of books on it, the one with no weight will go further.

f=ma Force= Mass x Acceleration

Work and Machines worksheet

13.4 Pg 80

1a) What is work? using a force to move an object
1b) A Machine: Anything which makes it easier to do work

2a) Pushing a Mower: Yes because you use the 'push' force to move the mower.
2b) Cleaning your teeth: Yes because you are using the 'push' force to move the brush around your teeth
2c) Cycling: Yes because you're moving your legs with the pedals and arms when you steer the bicycle.
2d) Reading: No because you're not using a force.

3) Why you need food for using force: Energy to keep your body functioning.

4) How to simple machines help: They help unscrewing nuts, opening cans, cutting wire and lifting cars which are things we would use a lot of energy on but with these machines we only need to use a little force.

5) other simple machines: Wheel/Axle, Nail, Carjack.

Pg. 81: 1-4

1) You need a set of pulley wheels and a rope for a pulley system
2) How does the pulley system easily lift the car engine: Because the pulley system divides the work into seperate ropes so each rope lifts a 100N. Another reason is because now there is a smaller force needed because of the greater distance.

3a) The chain: The chain is used as a rope like that of a pulley, you put the force on the chain it transmits the force to the wheels.

3b) The cycle's gears change the number of times that one turn of the crankshaft turns the back wheels.

4) Low gear helps you climb high places because the crank turns the back wheel once or twice which is enough to keep going up hill.

82 1-5: (TO BE COMPLETED)

What is a machine?

A machine is a man-made structure of a sort that helps in certain types of work; It does the same work as we would've done but instead it uses leverage to get the object to its destination. (e.g. pullies, ramps). It uses a longer distance but a smaller force meaning less work.

Erin Brokovich Review

The reason this picture relates to Erin Brokovich because it shows that companies, although they supply us electricity and other sources vital to our everyday life, they really are just doing it for the money and don’t care what happens to those around them. Such incidents have happened in Japan where the company was dumping mercury into the water poisoning the fish people ate and giving them weird diseases. These types of companies provide top quality sources for their recipients and all they’re concerned about is the electricity (or any other resource) reaching the recipients, their other actions are done regardless of taking the impact it will have on the lives of others. I always thought that these companies were very cautious about dumping waste and they’d do it in an environment friendly way. Turns out that some of them don’t even care about the environment and only for the money. So a lawsuit has to be put against them to hopefully persuade them, if not force them to stop threatening the lives of others.

Force Review

What is a force?

A force can be a push or a pull.

Can change the appearance of an object.

Can move in different directions.

Name 4 examples of forces and explain:

Gravity:

Is a force that has "pulled" us to the ground, the bigger the mass of the object using it, the greater the force.

Friction:

When two surfaces rub against each other, friction is formed. It slows down the speed of cars when the tires rub against the road. Thus it can slow down the speed of the rubbing objects.

Magnetic Force:

It can attract two magnetic metals depending on what pole the two magnets are classified as. Magnetic force attracts north and south poles together. Repels two of the same kind of poles.

Acceleration:

Acceleration is basically the speed something travels at. The acceleration can be slow, fast, moderate, and can cause the object to move in any direction.

Units of Force:

Force is measured in Newtons

Equation of Force:

Mass(kg, etc.)*Acceleration(km/h, etc.)= Force(N)

Food Web HW

The Producers in the food web are: Cactus Fruit and Flowering Plants.
The primary food consumers are: Small mammals and insects
The secondary consumers are: Snakes and Lizards
Predators are: Road runners, eagles and coyotes

Food Web in the Sagebrush-Steppe Ecosystem:

1. A. Plants are eaten by the Squirrels and other small rodents, insects, Pronghorn and other grazers.

B. Snakes are eaten by the Badger and Raptor

C. Insects are eaten by the Bat, Lizards and other small reptiles

D. Mountain Lions are not eaten by anything, unless they are decomposed by other organisms

2. If coyotes are continuously shot in the southwestern states, chances are, that the lizards and small reptiles, Pronghorn and other grazers will increase in population due to not enough coyotes to feed on them. This will reduce the amount of primary producers, which will be fed on by the growing population of the grazers. Insects population will decrease as they’ll be eaten by the growing population of the small reptiles, this actually helps the primary producers a bit, as one of their consumers population will decrease, they’re population will increase by a bit, maybe enough to feed the growing herds of the grazers.

3. If there was an increase in mountain lions population, then the populations of Pronghorn and other grazers will decrease, meaning there will be less grazers for the coyote to eat. This means the coyote will have to fall back on its other prey; small reptiles. With few grazers, the primary producers population will increase, meaning more food for the insects, squirrels and insects.

4. The effect Mesquite trees will have on the above ecosystem is that, the primary producers may have a tough time growing thanks to the Mesquite trees ability to gather plenty of water efficiently. This will cut down the variety of plants the primary consumers can eat, because they won’t have enough water. The primary consumers will have to compete for Mesquite plants, and there won’t be enough, due to lack of variety, so the primary consumers population will decrease. Without enough primary consumers, the small predators will decrease in population and same goes for the larger predators.