FarleyPhysics.com

Batteries

Click here to see how a battery works.

1. Click the box to show the battery.  Draw the battery in your notes and label the positive and negative side clearly.  The positive side of the battery is always the side with the extra knob on the end and the negative side is always the flat side.

2. With the voltage of the battery in the middle (dead battery), how many electrons are present on each side? You don’t have to count, just estimate.  Same, more on left, more on right.

3. Slide the “Desired Voltage” control to the right a little. Draw the picture in your notes and explain what this does to the amount of electrons on either side of the battery.

4. Slide the “Desired Voltage” control all the way to the right.  You now have a fully charged battery. Draw the picture in your notes and explain what this does to the amount of electrons on either side of the battery.

5. Draw the battery and explain which side is the positive and which side is the negative side of the battery, and why.

6. What would happen if you connected a wire from the positive to the negative side of the battery?

Conductivity

Use this simulation to study conductivity.

1. This simulation shows what happens when you connect a wire from one end of a battery to the other.  Draw the picture in your notes.  Increase the voltage of the battery by clicking the up arrow once.  Explain what happens to the electrons in the battery and the wire.

2. Slowly increase the voltage and explain what happens to the electrons as you increase voltage.  Also explain what happens to the energy of the electrons as voltage increases.

3. Switch the material to plastic and explain what happens to the electrons.

Circuits

Run this simulation to study circuits.

1. Pull out a battery, a light, a switch, and wires to make a circuit that looks like this:

Close the switch and explain what happens to the electrons and what happens to the light.

2. Open the Grab Bag and put a dollar bill in your circuit (right-click or Control-click to remove a wire) like this:

Is the dollar bill a conductor or a non-conductor?  Try everything in the grab bag and explain if it is a conductor or non-conductor.  You can right-click or Control-Click things to remove them.

3. Right click or Control-click on the battery and turn up its voltage.  Retry the pencil lead and the hand, and the dog to see if they are conductors.  What is needed to make them conduct electricity?

4. Turn on More Voltage and explain what happens in the circuit when the voltage gets too high.

5. Take the light out of the circuit and connect its wires together like this:

What happens when there is no light?

1. Return and go over Quiz.  Put into your notes as page 8.

2. Speed, distance, time notes [page 9]

3. Speed, distance, time problems. [page 10]

4. Adding a trend line to your graphs.  If there is time, add a trend line to each of your graphs.  Choose a linear fit and show the equation.  The slope of the line is the speed of the car.

Answer the questions here: rtqphysics-38-25.  Put your answers in a text document with the number and then your answer.  Then, include a short sentence either explaining why or summarizing the question and answer in some way.  You may work with one other person.

Example:

38: B A heated gas means energy is transferred to the gas from the heat source
39: C  10,7450 J input and 2420 J of work done leaves 8330 J of heat loss.
40: A 400 J of energy in and 25o J of work leaves 150 J
etc.

Put your document in Final Practice #1

More questions:

The boundary near a black hole where nothing can get out is called?

The theoretical tunnel created by two black holes is called?

A ray of light hitting a mirror at an angle of 35 degrees from the normal will be reflected at what angle from the normal?

The distance at which a lens focuses all parallel rays to a point is called?

For the following, use the simulation here.

The light from a lit candle refracts through a lens forming what?

The light from a lit candle placed further than the focal length of the lens forms what kind of image?

The light from a pencil placed closer than the focal length of the lens forms what kind of image?

Which of the following wave properties cause light to bend when it goes through a lens?

Go to the Black Hole Encyclopedia here.

Answer the following questions by writing the question,  an answer not using cut and paste, and including an image illustrating the answer.  You can use an Open Office document, a comic, or a Keynote.

Put it in the Black Hole Encyclopedia folder

Today you will add to yesterday’s assignment.  You must do your own searching for some of these answers.

Slide 9: What is the Event Horizon of a black hole?  Include an image.

Slide 10: Calculate the event horizon radius for a black hole formed by smashing the planet earth to a black hole size:  1. Go here to find the mass of the earth in kg, copy it.  2. Then search for “black hole event horizon” in Alpha and put the mass of the earth in there to find the event horizon radius.

Slide 11: What is the equation for the Event Horizon of a Black Hole?  You should see it in the Alpha page above. Describe the variables in the equation.

Slide 12: Hawking radiation: What is it?  Include an image.

Slide 13: What is a wormhole? Include an image.

For fun, search for your name in Alpha and find the information for your name.

Save your Keynote or comic and put it in the Black Holes Here folder on the server.  You can replace the old one or leave both.

Today we will be studying Black Holes by using the following website:

http://hubblesite.org/explore_astronomy/black_holes/home.html

You will create an 8 page Keynote presentation or an 8 square comic about black holes.

Here are the slides or squares you need to create.  Each one must have an image as well as text.  Use Command-Shift-4 and drag over the image to take a screenshot of it.  The picture will appear on your desktop.  Just drag it into Keynote or Comic Life.

Slide 1: Title
Slide 2: What is a Black Hole?  Provide a picture and an answer that has the question in it: A Black Hole is …
Slide 3: Find three objects in the sky that have black holes.  List them, include a picture of a black hole.  Your next three slides will be about these three objects.
Slide 4: Create a page/square about the first of the objects that has a black hole in it.  What is it called and what is it?
Slide 5 Create a page/square about another of the objects that has a black hole in it.  What is it calles and what is it?
Slide 6: Create a page/square about the third object that has a black hole in it.  What is it called and what is it?
Click Take a Journey by clicking “Begin Your Voyage” on the bottom right and go to Cygnus X-1.
Slide 7: What is Cygnus X-1 and What kind of light does it shine brightly in?
Slide 8: Get up close to Cygnus X-1 and explain what it looks like and why.

Put your finished keynote/comic file in the BLACK HOLES HERE folder on the server.

1. Take your measurements from yesterday and graph them with a spreadsheet.  Put Object distance on the x axis and Image distance on the Y axis.  Put your x numbers in order from smallest to largest for best results.  If your measurements are junk or the person who wrote them is not here, use mine.  My focal length was 10cm

2. Put  =f*A2/(A2-f) into C2 and drag the formula down to find the calculated image distance.  Be sure to substitute your lens’s focal length for f or the formula will not work.

3. Create a new graph with all three columns graphed.

Lab write-up:  Open an OpenOffice text document and include the following:

1. Your names on the left-top of the paper.

2. A centered title

3. An introduction.  What experiment did you do?  Put the word “Introdution” centered like the following and write what you did in a couple sentences.

4. Data.  Include your two graphs

5. Analysis. Center the word “Analysis” and discuss the graphs and how your measured image distance compares to your calculated image distance.

6. Conclusion.  Center the word conclusion and discuss the experiment and your results.

Save this as “your name lens lab” and put it in the “Lens Lab” folder.

Put all your measurements and answers in an open office document

1. Grab a lens and focus the rays of the sun or a light to a point.  For best results, get as far away from the light as possible.  Measure the distance from the lens to this point to find the focal length of the lens.  Write it in your document.

2. Get a meter stick, two ruler stands, a lens holder, a card holder, a card, and a candle.  Arrange the candle, lens, and card so the flame will shine through the lens and form an image on the card.  Experiment with your setup to make sure you can see the image of the flame.

3. Put your lens two focal lengths away from the flame (your focal length x2).  Move the card back and forth to find the best looking image of the flame.  How far away from the lens is the image?  How does this compare to the focal length of the lens?  Is the image upright or inverted?  What is the size of the image compared to the size of the flame (just roughly, you don’t have to measure the hight of the flame).

4. Move the candle three focal lengths away from the lens (focal length X3) and find the location of the image.  Is the image upright or inverted?  What is the size of the image compared to the flame?  How many focal lengths away from the lens is the image?

5. Move the candle 1.5  focal lengths away from the lens and find the location of the image.  Is the image upright or inverted?  What is the size of the image compared to the flame?  How many focal lengths away from the lens is the image?

Save your document.  We will finish tomorrow.

Go here to this lesson.  Click on the links at the top of the page to answer the following questions.

Answer the following questions in an OpenOffice document.

The Role of Light

1. We are able to see because?

2. Luminous objects are?  Illuminated objects are?

3. The sun is a _____________ object and the moon is a ________________ object.

The Line of Sight

What is the principle of the “Line of Sight”?

A light ray approaching a mirror is called?  A light ray that bounces off a mirror is called?

Where is the image that you see in a mirror located?  Copy the image that shows this into your questions.

Copy two of the images in the “check your understanding” section and explain why they are incorrect.

The Law of Reflection

Copy the image showing the Law of Reflection and explain what the “angle of incidence”, the “angle of reflection”, and what the “Normal line” is.

The law of reflection states that…?

Answer two of the “Check your understanding” questions.  Include images.

Specular vs. Diffuse Reflection

Explain what specular and diffuse reflection is.  Include images showing the light rays.

Find an image on the internet that shows specular reflection and diffuse reflection and explain where the specular and diffuse reflection is in your image.

Put your document in the Reflection folder.