FarleyPhysics.com

Page 19

Notes on voltage

Voltage for lights in series:

Use this simulation to make a circuit with one battery, one light, and a voltmeter.

2. Measure the voltage across the battery, the voltage across the light, and the voltage across one of your wires.  Fill in and write this sentence in your notes: The _________ of the battery is __________to the voltage across the light.

3. Now add a light.  What happens to the voltage across each light.  Write this as a sentence and draw a picture.

4. Measure the voltage across both lights.  What is this equal to?

5. Add another light.  What is the new voltage across each light and across all the lights?

6. Put 4 total lights in the circuit.  What is the new voltage across each light and across all the lights.  Is there a pattern?  What is it.  Draw a picture and write a statement that explains what happens to voltage across each light.  Also, what is the voltage across all the lights?

7. Turn your battery voltage up and remeasure the voltages across each lamp and all the lamps.  Write down what you find.

8. Delete lights and see what happens to the brightness of the lights that are in the circuit.

Voltages for batteries in series

1. Delete your battery and add two new ones in series.  Measure the voltage across each battery and both batteries.  If you put batteries in series, what happens to the voltage in the circuit?  Draw the circuit in your notes.

2. Put three batteries in series.  What happens to the voltage in the circuit?  What happens to the brightness of the lights?  What happens to the voltage across each light?  What happens to the voltage across all the lights?

Be sure your pages are correct in your notebook:

page 14: Electric Field Online Lab

page 15: Wave Quiz Questions

Page 16: Electric Fields and Static Electricity

Page 17: Electric Field Review

1. Quiz Returned

Page 17 in notes

2. Electric Field Review

3. Charge by friction, contact, and induction.

4. Work on your notes and your comic.

Quiz tomorrow and collecting notebooks tomorrow.

Create a comic about electric fields:

Note, to take a picture of a simulation or anything on the screen, press Command-shift-4 and drag a box around what you want.  The image will appear on your desktop.

Square 1 Comic title “Electric Fields” real large with the image of an electric field behind it.

2. The field from a positive charge, text explaining what direction the field lines point.

3. The field from a negative charge, text explaining what direction the field lines point.

4. The field from a dipole (one positive and one negative), text should explain what a dipole is.

5. Likes repel (explain it with an image and text)

6. Opposites attract (explain it with an image and text)

7. Rubbing a balloon against a sweater, what happens?

8. Bringing a charged balloon next to a wall, what happens? (use command-shift-4 to screenshot yesterday’s simulation).

9. Show the highest level you can reach with Electric Field Hockey.  Show it with Trace on and Field on.

Put it in the Electric Field Comic folder at SLAMA/Class Folders/Physicsabc

Page 16 Electric Fields and Static Electricity

Fields

Run this simulation to answer the following questions:

1. Click the Add button to add a charge.  Draw the field and the charge in your notes.  Use the direction of the arrows to determine the sign of the charge.  Click Properties to see if you are right.

2. Click Add to add another charge and explain what happens.  Do they attract or repel each other?  Draw a picture and write this as a statement in your notes that will help you remember it on a quiz.

3. Grab the External Field arrow and have the field point to the right.   Explain where the charges move.   (in the direction of the field or opposite?).  Draw a picture and write this as a statement in your notes that will help you remember it on a quiz.

Be sure you know the answer to the following question: ______ charges move in the same direction as an electric field and _________ charges move in the opposite direction a field is pointing.

Static Electricity

Now run this simulation and answer the questions.

1. Rub the balloon agains the sweater and explain what happens to the sweater and the balloon.

2. Release the balloon between the sweater and the wall.  What happens?  Explain why in terms of charge.  Draw a picture and write this as a statement in your notes that will help you remember it on a quiz.

3. Bring the balloon toward the wall and explain what happens to the negative charges in the wall and what happens to the positive charges.  What happens to the balloon, and why? Draw a picture and write this as a statement in your notes that will help you remember it on a quiz.

4. Is the balloon attracted more to the sweater or to the wall?  Why?

5. Reset and add two balloons.  Rub them both against the sweater.  Do they attract or repel each other? Why?

Static Shock!

Run this simulation to see how static shocks work.

What happens when you rub John’s foot on the floor?

What happens to the charge when you bring John’s finger near the door handle?

How is John like the balloon?

Hockey

Play Electric Field Hockey and see what level you can reach.  Draw your highest level in your notes.

Quiz Notes Comic

1. Take every question you got wrong and turn it into a comic square.  Do not copy the question and answer word for word.  You should make it into one statement.  The image should illustrate the question and answer.

Return Wave Quiz

Page 15:

1. write every question and answer that you got wrong in your notes.  Include an explanation.

2. Take every question you got wrong and turn it into a comic square.  Do not copy the question and answer word for word.  You should make it into one statement.  The image should illustrate the question and answer.

We will take the Wave Quiz again on Friday.  You may not use the current wave quiz as notes for Friday’s quiz.

Page 14 in your notes

Electric Field Online Lab:

1. Use this applet to sample the electric field around a charge at least ten times with some close and some far.  Draw this in your notes.

2.Where do all the arrows point and how does the length of the arrow vary the further you get from the charge?

3. Clear the arrows, clear the charge, and add a negative charge.  Sample the field by drawing arrows around the charge and draw it in your notes.

4. Which way do all the arrows point for a negative charge?  How does the length of the arrows vary as you get further from the charge?

5. Clear the arrows, clear the charges, go to patterns and make a dipole.  Draw the field.

6. What direction does the field always point around positive charges?  What direction does the field always point around negative charges?

7. Which way does the field point between the charges in a dipole?

8. Create two positive charges next to each other and draw the field.  Where do all the arrows point?  Where is the arrow pointing in between the charges?

9. Create a line of positive charges and a line of negative charges and draw the field.  Remember the arrow only shows the strength of the field at the point tested, it doesn’t mean anything about where the tip is.

10. Create 4 positive charges all in one place and then one negative charge.  Draw this electric field.

Run this applet to see the electric field in 3D.  Display: Field Vectors and drag your mouse around to look at the field from different angles.  Look at different Field Selections.

11. draw field for the dipole (do your best)

12. draw the field for a charged line

To prepare, get your notes in order by filling out your table of contents:

Page 6: Notes on amplitude, frequency, wavelength. standing waves. longitudinal and transverse waves.

Page 7: Electromagnetic spectrum web research

Page 8: Doppler Effect

Page 9: Sound waves

Page 10: Wave equation problems

page 11: Things to know about waves.

Page 12: Interference and beats

Page 13: Polarization and Refraction

Page 13

Refraction

Go here to learn about refraction.

1. What is refraction?  Draw a picture in your notes that illustrates how refraction works.

2. Go to the Refraction simulator. When the flashlight’s angle is zero degrees, 45 degrees, 80 degrees, and 90 degrees what is the angle of light in water?

3. Change the water to diamond and repeat the #2 experiment.

4. What law describes how light refracts at different angles as it passes from one transparent medium to another.

5.  What happens when the flashlight is inside the diamond between 90 and 25 degrees?  This is why diamonds are so shiny.  The light bounces around in the diamond and only gets out when it is headed almost straight out to your eyes.

6. As the index of refraction of the medium increases, what happens to the angle the light bends?

Polarization

Go here to learn about polarization.

1. Light is what kind of wave?

2. What are light waves created by?

3. Is light a transverse or longitudinal wave?

3. A light wave that is vibrating in more than one plane is referred to as ________________ (it’s in red).

4. When all the light vibrates in a single plane, this is called _________________________ (in red also)

5. Explain the 4  different ways to polarize light and draw a picture of each.

4.