FarleyPhysics.com

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.

Run the simulation linked here.  Take a screenshot of each step in the experiment below #7 (Command-shift-4 and drag a box over the screen).  Put it in an OpenOffice document and drop it in the Geometric Optics folder.

1. Move the pencil closer and further away from the lens.  How does the image of the pencil move as you move it closer and further from the lens?

2. Explain what happens to the size of the image as you move the pencil closer and further.

3. Move the curvature of radius of the lens.  Explain what happens to the image as the curvature changes.

4. The tiny x’s near the lens show the focal point of the lens.  What happens to the focal point as you change the radius of curvature?

5. Turn on “Virtual Image.”  Move the pencil closer to the lens until it is inside the focal point of the lens.  Where is the image when the object is within the focal length of the lens?  This is called a virtual image.

6. Explain what happens to the virtual image as you move the pencil closer to the focal point.

7. Are virtual images upright or inverted (upside-down)?

Experiment:

1. Turn on the ruler and change your radius of curvature until the lens’s focal length is 50 cm.

2. Put the pencil 100 cm away from the lens and measure the image’s distance from the lens, if it is upright or invertedl, and what is its size compared to the pencil?

3. Real images are images where light comes to a focus.  Virtual images are where light looks like it comes from (it’s an illusion, not real).  Is the image in #2 real or virtual?

4. Put the pencil 75 cm away from the lens.  Describe the location, orientation, real/virtual, and size of the image.

5. Put the pencil 100 cm away from the lens. Describe the location, orientation, real/virtual, and size of the image.

Focal Length

1. Grab a couple different lenses.  Take them outside and focus the Sun to a point (use inside lights and get at least 10 ft. away to simulate sun if it’s cloudy) .  Measure the distance from the lens to the point where the rays focus to the smallest point.  This length is called the focal length of the lens.  Measure at least 2 lenses with different focal lengths.  Write these measurements down in an OpenOffice document.

2. Find an image online of light coming through a lens and focusing to a point at the focal point. Put this image in your document.

Telescope

1. Use a long focal length lens and a short focal length lens to make a telescope.  Switch the lenses to find out how to make the best telescope. Go outside and look at the hills. Measure the distance between the lenses when the telescope works best?  Explain where the lenses are and the distance between the lenses.  Where is the short focal length lens and where is the long (switch them to see what makes the best telescope)?

2. Is the image upright or inverted (upside down) in your telescope?

3. Do a search for Telescope lenses and find out how a refracting telescope works.  Copy a picture of the lenses of a refracting telescope to your document.

Microscope

1. Create a microscope with two lenses with different focal lengths.  Move the eyepiece lens around until you actually make something small and close, big.  Record the distance between the lenses and if your image is upright or inverted.  Also, explain where the long focal length lens is and where is the short.

2. Do a search for microscope lenses and find out how a microscope works.  Copy a picture to your document showing all the parts of a microscope (just the lens parts).

Put your document into the Lens Exploration folder.

Today you will write a lab report based on your Refraction experiment and analysis.  Please be as short as possible with all the sections. Do not write a lot of blah blah.  One to three sentences for each section is best.  The analysis section will take more, but don’t get crazy

Open a new text document

Include

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

2. A centered title like the following:

Refraction Simulation

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:

Introduction

I used a refraction simulation to find the angle of light through air and the angle that the light is refracted when it enters water, glass, and two mystery materials.  (don’t copy my words).

4. Data.  Include your four final graphs that you took the Sine of the angle, with equations and trend lines.  Center the word “Data” and put your four graphs under it.

Data

5. Analysis. Center the word “Analysis” and discuss the graphs and equations by answering the following questions:

Analysis

What index of refraction did you get for each substance?  This will be the slope of your line.  If it is less than one, you did your graph upside-down.  your index is 1/slope.

How does your index compare with the accepted value?  Find indexes here.

What are your mystery substances?  Compare your index to the ones linked above.

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

Save this as “your name refraction” and put it in the “Refraction Lab” folder.

Today you need to analyze the data and the graphs.

1. Take the sine of each angle by putting “=sin(radians(A2))” in C2 and “=sin(radians(B2))” in row D2.  Label these rows “Sine of Refracted Angle” and Sine of Angle in Air.”  The word Radians is to convert degrees to radians.

2. Make a graph of columns D and C by dragging to select columns D and C.  Name the graph and its axis like the following:

3. Double-click the graph and go to Insert > Trend Line and fit a linear line to your data.  Be sure to check “show equation.”

4. The slope of your graph is something called the Index of Refraction.  For water, it should be around 1.33.  If you got 0.75, you reversed your x and y axes.  Just invert your value 1/0.75 and you will have the right number.

5. Save the spreadsheet!  Do not copy the graphs into a document yet.

Today we will begin a scientific paper on refraction.  To get started, follow the directions below.

1. Start this simulation on refraction and open a new spreadsheet to put your measurements into.

2. Turn on the laser by pressing the red button and play around with the simulation to see what it does.

3. Experiment: Measure the  angle of the light in water (angle of refraction) for ten different angles of incidence (the angle in the air).

4. Put your numbers in a spreadsheet with the angle in the water in the A column and the angle in the air in the B column.

5. Graph the data in an x-y scatter graph and be sure to title your graph and label the axes.

6. Do the same experiment and graphs for Glass, Mystery A, and Mystery B.  In OpenOffice, press the Sheet tabs to enter new data and make a new graph.  Insert > Sheet to make another sheet for Mystery B.

Save your spreadsheet  so you can work on it more tomorrow.

Today we track a spaceship using a spreadsheet.

Position of Spaceship

A spaceship travels through space obeying the following equation:

x =60t + -250Cos(0.2t) – 250,  where x is position in km and t is time in seconds.

Graph the position vs. time of this spaceship for 100 seconds.  To do this, use the following steps:

1. Put “Time” in A1 and Distance in B1. then zero in A2.

2. use = A2+1 in the first column and drag down to get all the integers from 0 to 100 into the A column.

3. enter “= 60*A2 + 250*cos(0.2*A2) – 250″ into B2 and drag the formula down (copy it exactly for it to work).

4. Create an x-y scatter graph of the data, title it, and label the axes with the correct units.  Copy the graph into a text document.

5. Answer the following questions in your text document using your graph and spreadsheet:

6. What is the position of the spaceship at 0 seconds, 20 seconds, 50 seconds, and 100 seconds?

Velocity of a Spaceship

The velocity of the spaceship is given by the following formula:

v = 60 – 250*Sin(0.2t)

1. In C1, put “Velocity”, In C2, put the formula “=60 – 250*Sin(0.2*A2)” and drag down to calculate the formula for all the cells.

2. Drag to select all the numbers and labels from A1 to C100 and create an x-y scatter graph.  Label the graph and keep the legend because now it should have useful information.

3. Copy the graph to your text document and answer the following questions in the text document:

4. What is the velocity of the ship at 0, 20, 50, and 100 seconds?

Acceleration of Spaceship

The acceleration of the spaceship is given by the formula: a = 250Cos(0.2t).

1. Chart the values in column D. Use the formula “=250*Cos(0.2*A2)”

2. create a graph of position, velocity, and acceleration.

3. Find the acceleration at t = 0, 20,50, and 100 seconds.

Answer the following questions in your text document:

Find the position, velocity, and acceleration of the spaceship at 200 seconds.

Turn the text document into the Spaceship folder.