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).