solutions to practice problems

Solution to Practice Problems

Unit 4: Advanced Concepts in Forces

Nov. 30 – Jan. 7
Goals
· Be able to add forces in two dimensions.
· Understand and apply conditions for equilibrium.
· Calculate the frictional force when given the coefficient of friction and vice versa.
· Determine the normal force, and the parallel and perpendicular components of gravity for inclined plane problems and solve for acceleration.
· State and apply equations for centripetal acceleration and force.
· Distinguish between the centripetal force and the fictitious centrifugal force.
· Analyze examples of circular motion in terms of Newton's three laws of motion.
· State and apply Newton's universal law of gravity.

Important Dates
Friction Lab : due Dec. 7
Moons of Jupiter Handout: Dec. 17
Homework: Dec. 18
Unit Test: Jan 7

From the Text book:
Friction: p. 130-134
Forces in 2D: Sections 7.1 and 7.3
Universal Gravitation: Ch. 8

Web Support:
General Tutorial http://www.glenbrook.k12.il.us/gbssci/phys/Class/BBoard.html

Moons of Jupiter simulation
http://www3.gettysburg.edu/~marschal/clea/juplab.html

answer key forces review

Forces Review Answer Key

skydiver answer key

Solution Skydiver

Unit 3 goals - Dynamics

Unit Three – Dynamics

Goals
Draw Force Vectors.
Calculate Weight.
Solve Problems with Net Force.
Know that when an object is at rest or moving with constant velocity that that Fnet = 0 and all of the forces are balanced.
Understand what terminal velocity is and how it is reached.
Be able to explain why all objects in freefall have an acceleration of 9.8 m/s2
Understand that forces are interactions between two things and that each object exerts an equal and opposite force on the other.
Know Newton’s Three Laws of Motion by name.
In general, understand Newton’s 3 laws and apply them to explain motion.

vector review worksheets

Motion in 2 Dimensions Practice

Review Problem Answer Key second set

Review Problems 2 Answer Keypdf

Review Problem Answer Key

Review Problems Answer Key

Downloading Logger Pro

Update. I now have copies on disk. Borrow one from me if you want to install it.


Available for just a short while.
As students of Grant High School, which has a site licence for Logger Pro, you may install Logger Pro on your home computers.
If you wish to do this, connect to this link. (It's dead now.)
This will be a very slow operation if you do not have broadband.
Alternately you may bring me a burnable CD, and I will make you a copy.
Thanks.

Freeman Dyson is speaking in December

At 85 he has not just been an extremely important physicist, but he has been involved with most of the important physics that happened in the 20th century. His recent notoriety is due to his coming out as a global warming denier. Expect some questions about this.

I don't know much about Weil and haven't heard of the others on the lecture series line up. Dyson is a big deal though.

Here's a fairly recent NYTimes story on Dyson.

Here's a link to the ISEPP lecture series homepage.
Lectures are spread through the year and occur downtown at the Schnitzer.

I can get you tickets if you give me some warning.

the power point presentation from 9/15

http://www.mediafire.com/?sharekey=c25c6af425000f49d956df2962098fcbe04e75f6e8ebb871

You will need your own copy of powerpoint

Making an Online homework account.

Please go to this link and start an online homework account. Click on "get started" and then choose "I need a UT EID". In the next window choose "get a UT EID". After you submit your information it will send your ID code to your email account. With this code you will will sign in to my class and start the first assignment. You may proceed to sign in now or bring your EID code and password on Wednesday. On next Monday we will log in as a class, I will start accepting your enrollment and we will start the first assignment.

This is how to sign in:
Return to the link above and log in.
You will then need to select a class based on a unique number. For Physics the unique number depends on your period. For per 4: 2234, for per 5: 2235, for period 6: 2236. . Enter the number 223... and then select look up course info. Scroll down by clicking the arrow on the window that appears through the many other classes designated with that unique number until you find Physics (Grant High school 2009 Fall). It will probably be one of the last ones. Select it and then select request enrollment.

I will have to admit you into the class. The next time you log in, after I admit you, you will be able to use the "select course" and "select assignent" windows to start the Kinematics homework.

Unit One: Kinematics in 1 dimension.

Unit 1: Kinematics in 1 Dimension

Goals:1. Know and apply the definition for average velocity.
2. Know and apply the definition for average acceleration.
3. Differentiate instantaneous and average velocity.
4. Interpret graphs of position, velocity and acceleration, including through the use of slopes and the area under the graph.
5. Draw position, velocity and acceleration graphs for described motion.
6. Know the acceleration due to gravity.
7. Solve problems by using 5 basic mechanics equations.
8. Properly use sign conventions for positive and negative acceleration and velocity.
9. Describe sources of error as either random or systematic and suggest basic ways of reducing error such as controlling variables, doing multiple trials, collecting data over a wide range and using big sample sizes.

Homework: Due Date
Letter to Teacher & Safety Contract Wed, 9/9
Lab 1 data presentation Mon, 9/14
Understanding motion through graphs(wksht) Tues, 9/15
Lab 1 report Fri, 9/18
First Quest hmwk assignment Fri. 9/25
Inst. & Ave. Vel…(wksht) Fri, 9/25
Solving Problems in Phys(wksht) &
Review packet (not graded) Mon. 9/28

Unit Test : Tuesday 9/29

Checking Grades

Here is a link to the Parent Assist website.

Many Grant teachers will use this district provided program to maintain and post their grades. You will also be able to monitor attendance and check personal information. I will update grades after every major test and lab, but I might not get every late assignment or retake in the gradebook promptly.
To use this website you will need to get a personal code from the Grant High School office. If you have a code from last year or for any other child it should still be active.

Welcome Back & General Information

The 2008-2009 school year has started. Welcome to Physics.

Here is some general information about how the class runs.

Grades:
Approximately 50% Tests, 30% Labs, 20% homework

Tests: About twice a quarter, with semester finals also. Retakes are available, but only half the missed points are recoverable.

Labs: Although we’ll have weekly hands-on lab assignments, I’ll only have you write up formal lab reports about twice a quarter. (The first one will be due Sept. 21.) Late labs are penalized at 10% a week.

Homework: Most homework will be submitted online through the web site https://quest.cns.utexas.edu/ It will be graded for accuracy, but on a generous scale because I recognize that homework is practice and created to find mistakes. Students who have difficulty getting internet access should talk with me. Accommodations will be found. No late homework accepted except for excused absences.

Grading Scale: 100-90 A, 90-80 B, 80-70 C, 70-60 D, <60 F.

Supplies:
Textbook
Notebook, or section of a notebook
Calculator
Protractor
Graph Paper

Greenhouse effect simulation

http://phet.colorado.edu/simulations/sims.php?sim=The_Greenhouse_Effect

Extra Credit Opportunity (5 points in the homework category for a thoughtful 1.5 page discussion of how the program simulates global warming and the results of your experimentation)

Play around with the simulation. I suggest you uncheck the box to show all photons as this will simplify the display.

First experiment with using glass panes instead of greenhouse gases.
Note what the red and yellow dots represent and what happens to the yellow photons when they strike the panes from above and below and what happens to the red photons when they strike the panes from below. Note how as you add more and more panes, new equilibrium temperatures are established. How do the temperatures relate to the number of glass panes?

Next experiment with the different levels of greenhouse gases and different amounts of clouds. How does the simulation show greenhouse gases being related to temperature? What do greenhouse gas levels similar to the ice ages or pre industrial revolution (in 1700s) do to the temperature? What happens if you set the levels at their maximum or minimum?

If you're doing this for extra credit, you need to turn in a written reflection on the results of your experimenting. It should be about a page and a half. It should focus on how the simulation shows the greenhouse effect and how the temperature depends on the levels of the gases. It can also include your reflections on a number of other things too such as your questions or your thoughts about the accuracy of the model and the pros, cons and inherent limitations of a model of this sort.

first reading on global warming

The Greenhouse Effect - Reading

Publish at Scribd or explore others:

Climate Change - Unit 7

Unit 7 - Climate Change
Goals:
1. Show a basic understanding of the greenhouse effect and its role in climate change including:
naming the most important greenhouse gases and their major sources;
describing the absorption, reflection of emission of EM radiation in the atmosphere and the earth’s surface;
describing historical trends in CO2 levels and global temperatures;
describing major predicted and realized consequences of climate change.
2. Describe the development of scientific consensus around climate change,
including the sources for relevant data, the use of computer models and the role of nonconsensus points of view.
3. Compare and contrast varying solutions to climate change that fall into these categories:
Economic/public policy
Technological
Personal choice
4. Write a letter to an elected official or a letter to the editor that:
demonstrates an understanding of the science and evidence of climate change
proposes a set of actions that you might personally take or, for society and/or policy makers to take
demonstrates a thoughtful weighing of risks and consequences for that set of actions.

Key Questions
What is the greenhouse effect and how does it relate to global warming?
What are the current and future impacts and effects of climate change?
What are the benefits and drawbacks to the various possible solutions of climate change?
What is our personal, individual responsibility to climate change?
What should government’s role be in addressing climate change?

Homework and Important Dates (assignments are due on the following class day)
4/20
Unit intro. Discuss groups and homework.
Read The Greenhouse Effect, and answer questions. Find one resource on your group’s topic.
4/21
Group collaboration and poster preparation
4/22
Sharing and discussing posters. Computer simulation.
Reinforcing Feedback homework packet.
4/24
Thingamabob game
Write Response to Game.
4/27
Political Solutions to an international problem
Reading on either carbon taxes, cap and trade systems or the Kyoto Protocol.
4/28
Share out in groups about readings.
4/30
Wedge stabilization activity
5/1
Present solutions to Wedge activity
Write Response to wedge activity
5/4
IQ^2 podcast
5/5
5/6
Letter to editor due Friday 5/8

answers to ch 17

Answers to Ch. 17

I have no degrees key in blogger. Almost all numbers are numbers of degrees.

31 a. 53, b. 106
33 1.46
41 a. 25, b. 29
42 1.24 *10^8m/s
54 red light, 12, blue light 11.8
57 angle in glass is 28, strikes upper side at 62 from normal, reflects, strikes far side at 28 from normal, refracts into air at 45.
58 note incident angle is 30. for red 19.3, blue 19.1,

Light Unit

Goals:
1. What is Light?
Be able to describe and give effective examples of the strengths and weaknesses of the two models of light.

2. How does light behave?
A. Reflection:
i. What is the law of reflection?
ii. Be able to locate images and make ray diagrams.

B. Refraction:
i. What is refraction?
ii. What is Snell’s Law?
iii. How did we determine a law for refraction?
iv. Be able to solve problems and draw ray diagrams.

C. Colors:
i. What are primary, secondary and complementary colors?
ii. How are colors produced by dispersion, addition and subtraction of light?

D. Lenses:
i. Be able to draw ray diagrams for converging and diverging lenses.
ii. Identify images as real or virtual.

E. Others:
i. Explain the production of rainbows and the color of the sky and sunset.
ii. Summarize how diffraction and interference apply to light.

Assignments (tentative)

Color Concept Development Worksheet 28-1 due 2/25
Reflection concept development sheets 29-1, 29-2 due 2/27
Data tables and graphs for refraction lab due 3/2
Refraction Lab report due 3/10
Snell’s Law Worksheet due 3/11
Testing a Particle Model of Light due 3/13
Read Chapter 17 : Questions 31,33,41,42,54,57,58 due 3/16
Lens Worksheets due 3/20
Review Handouts due 4/2

Unit Test April 3

Semester 2, Unit 1: Sounds and Waves.

Goals:

1.Explain what a wave is.
2. Differentiate between longitudinal and transverse waves
3. Correctly use the vocabulary: medium, pulse, crest, trough, compression, and rarefaction.
4. Define and apply the following wave characteristics: period, frequency, velocity, wavelength, amplitude, and energy.
5. Apply the following relationships: T=1/f and v =f*wavelength.
6. Explain how standing waves are produced and correctly use the terms nodes and antinodes.
7. Explain the following wave behaviors, interference, beats, resonance, doppler effect and sonic booms.

Homework:
p.335, practice problems 2,3,5,6
p. 345 Q 16,17,18, and p.346 Q 42
p. 369 Q 13,14, 16, 18, 19, 42
Wave Superposition Practice Sheet
Speed of Sound Lab Questions
Wave Review work sheets

Test Fri, 2/20
On the block day 2/19 or 20 we’ll do an activity for the next unit on light.

Here’s the website I’ll be showing a lot of : http://www.kettering.edu/~drussell/Demos.html

Unit 5: Momentum Energy and Conservation Laws.

This unit was going to be rushed anyway and thanks to the snow days it will be really rushed.

The final exam the last week of the January will serve as the unit Final also.

There will be several small homework assignments from Chapters 9 and 10

The lab, Conservation of Momentum in 2-D wil be due Tuesday Jan 20.

Review Guidelines and copies of old tests will be distributed during the week before the final.