29 Oct: Homework set 7 solutions are posted.  Electric current quiz questions for Wednesday are here.

22 Oct: Homework set 6 solutions are posted.  Next week's estimation problem is posted.

12 Oct:  Exam 1 is here and the solutions are here. 

8 Oct: The estimation question for next week is posted.  Also, Children's Festival pictures are here.  I'll try to post more pictures next week.

24 Sept: At the beginning of class Monday, be prepared to answer this question.

Children's Festival Volunteers:

Shift	Names
9-11	William McMillen, Megan Johnson, April Clark, Tameka Davis, Candis Crenshaw, Fitson Aberra, Adrienne Raguini, Justin Stowall
11-1	Wilfred Custodio, John Collera, Trieu Dang, Alison Afsharm, Nikita Simpson, Lisa O'Neill, Kimberly Miller, Melanie Andrade
1-3:30	Al Delos Santos, Mandy Heinzen, Zakeia Alexander, Manuel Aguilar, Nick Doud, Ridgely Carter, Kindra Jones, Brianna Howell, Delaney Simmons

13 Sept: Homework 1 solutions are posted (see the link in the homework page).  If you need a physics tutor, check this list.

31 August: Here are some tips on getting a good grade  (Word format) (text format) in Physics 101 from a former student .

27 August: Here are your lab TA's:  Mike Maskell (10-12 and 12-2) and Mustafa Canan (2-4 and 4-6)

26 August: Make sure you purchase the 'PRS Interwrite clicker' at the bookstore.  You will need it for the class participation part of your grade.  You will also need to activate your clicker at  http://www.odu.edu/af/classroomcentral/ (click on the
'Clicker Activation' button on the left hand side [not working yet as of 8/26])

Privacy Concern: If you do NOT want other people to be able to see your homework grade when it is returned, let me know.  I will assign you an ID number to use on your homework instead of your name.


Syllabus

2002 Vugraphs not in course notes:

2003 Vugraphs not in course notes:

Homework Schedule (subject to change):

1. Putting magnets on your body will improve your energy fields.
2. Putting magnets on your body will reduce muscle aches and pains.
3. The moon causes ocean tides.

Chapter 8 extra problems:

Extra 1: An astronaut with a mass of 70 kg is in a space station rotating to give him the same weight as on Earth. What is the weight of the astronaut (in pounds) on the Earth? Something goes wrong and the rotational velocity of the space station doubles. What is the apparent weight of the astronaut now (in pounds)?

Extra 2: Neglect the weight of a meter stick and consider only the two weights hanging from its ends. A 2 kg weight hangs from one end and a 4 kg weight hangs from the other. Where is the center of mass of this system (the point of balance)? How does your answer relate to torque? (Hint: This is the same as Problem 3, but with the numbers changed.)

Hint for Chapter 8, exercise 48: The phrase 'How does the wheel respond' means 'Does the wheel rotate? If so, in which direction does it rotate?'

Why estimation problems are important:

Estimation problems are designed to help you understand the difference between and a million and a billion and to help you get comfortable with large numbers (ie: exponents).  We consider questions like this in daily life and in politics all the time.  Is a $500 billion deficit a lot?  Is 1000 dead Americans in Iraq a lot?  Should I buy a lottery ticket? How much impact does my household trash have on the environment?  

These are questions where you will need to supply some of the information (ie: estimate).  For example, in the first question, you need to estimate the thickness of a card.  Your answer should almost never have more that one significant figure (that's the number before the 10^x) because your estimate will never be that accurate.  

Sample question: How far could you walk in a year?  
Sample answer: I walk about 3 miles per hour.  If I walk 12 hours per day and 365 days per year then I can walk
    3 mi/h * 12 h/day * 365 day/yr = 13140 mi/yr = 1 * 10^4 mi in one year
Note that 13140 mi is wrong because it implies that you know the answer much better than you actually do.  The 3 mph might be 2.5 or 4.  The 12 hours/day might be 8 or 14.  You might have to take some days off.   1*10^4 implies that the answer is not very precise.

Chapter 1 Estimation: Your chance of winning MegaMillions is about 1 in 10^8 (ie: one in one hundred million).   This is the same probability as drawing the only correct card from a deck with 10^8 cards.  If you stacked 10^8 cards in a single pile, how tall would that pile be (in meters)?  Which distance is this closest to: a) a tall building (100 m), b) a small mountain (1000 m), c) Mt Everest (10,000 m), d) the height of the atmosphere (10^5 m), e) the distance from here to Chicago (10^6 m), f) the diameter of the Earth (10^7 m), g) the distance to the moon (4x10^8 m)?

Estimation 2: The average American drives 12,000 miles per year.  How many hours does one average American spend in her car each year?  How many total hours do ALL Americans spend in their cars each year?  How much is this in years?  In lifetimes?

Estimation 3: How fast does your hair grow?  Express your answer in a) inches per year, b) m/s, and c) miles per hour.

Estimation 4:  Can you run fast enough to have the same momentum as an automobile rolling at 1 mi/hr?  Make up reasonable figures to justify your answer.  (Obviously your answers will differ for a Mini or for a huge SUV.)

Estimation 6: How many people in the US are airborne (ie: in an airplane) during class on Friday?

Estimation 7: In the movie Spiderman II, Spiderman stops a runaway New York City subway train by attaching his webs to nearby buildings and pulling really hard for a long distance.  Assume that the subway train has 6 cars, each of which has about the same mass as a tractor-trailer.  Assume that he exerts the force over a distance of 1 km.  How much force does he have to exert to stop the subway train?  Give your answer in Newtons and in tons (1 ton = 10^4 N).  How does this compare to the force that you can exert?  (Hint: estimate the kinetic energy of a subway train at normal speed, then figure out the work needed to stop the train, then figure out the force needed.)