Old Course Page

Physics 102 (Spring 2003) Conceptual Physics II

News:
25 April: Answers to the sample final are here  Answers to homework 11 are posted.  Answers to the practice homework are in the back of the Practicing Physics workbook.

23 April: Sample final exam (from 2002) is here

8 April: Exam 2 is here and the solutions are here

20 March: Extra Credit News:
The Tidewater Physics Olympics will be Saturday, 3/22, from 8:15 to 12:00 at Landstown HS, 2001 Concert Drive, Virginia Beach.  Let me know if you want to help.

The tour of Jefferson Lab will be Friday, March 28, from 10 to 11:30 at Jefferson Lab, 12000 Jefferson Av, Newport News, VA.  We will meet in the main building (CEBAF Center).  You can find directions to JLab here.  CEBAF Center is the yellow building on the site map.  Let me know by Monday if you want to attend.  I will need to give a full list of attendees to the security guards.

Comic Book Physics will be the title of the lecture given at Jefferson Lab at 7:00 PM on Tuesday, March 25.  If you attend, let me know and I will award you 30 points to the homework set of your choice (actually, we will allocate it so that it improves your HW grade the most).  For directions, see the previous item.

24 Feb: Exam 1 is here and the solutions are here.

You can find the powers of 10 video that we saw the first day of class on the web at http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/index.html

The  syllabus is here

Exam 2 from 2002
Exam 2 answers from 2002
Exam 2 sample test
Exam 2 sample test answers

You can download the lecture notes from here

Demos so far (indexed by chapter):

*Do it for fun.  It won't be graded.  You don't have to write it up in your homework.  (Elementary school students would love some of these projects.  My kids do.)

Estimation 1: Pressure increases with depth under water.  If you dive 3 m (about 10 feet) down in a swimming pool, what is the pressure on your body?  How much total force does the water exert on the front of your body?  On the back of your body?  Give your answer in Newtons and in tons (1 ton = weight of 1000 kg = 10^4 N).

Estimation 2: If all the people in the world are crowded together as closely as possible, how much area would we occupy?  Give your answer in m^2 and in km^2.  How does your answer compare to the area of Virginia Beach (about 400 square miles or 1000 km^2)?

Estimation 3: How many people in the world are picking their nose right now (or at any other specific time)?  There are about 6*10^9 people in the world.

Estimation 4:  How much heat does a person emit on average?  Assume that all of the calories you eat in one day are converted to heat.  Give your answer in Watts = Joules/second.  Compare your answer to the power used by various light bulbs (4 W nightlight, 25 W bulb, 100 W bulb, 500 W halogen bulb , ...) or electric heaters (1500 W heater).  Note that a food calorie (C) is 1000 physics calories (c) and 1 physics calorie is about 4 Joules (1 c = 4 J).

Estimation 5 (extra credit):  A large electric power plant generates 1 Billion Watts of electricity.  If its thermodynamic efficiency is 1/3, how much coal does it need to burn each year?   Burning coal produces 10^7 J/kg.  Express your answer in tons and in railroad  carloads (100 tons each).  How much uranium would a nuclear power plant need each year?  Uranium releases 10^14 J/kg through nuclear fission.  Express your answer in tons.

Estimation 6 (extra credit):  One of the loudest sounds ever made on Earth was from the eruption of the volcano Krakatoa. How long would it take the sound from that explosion to travel completely around the Earth (and return to its starting point)? Give your answer in hours (or, if necessary, in days or weeks).

Estimation 7 (extra credit): On average, how many people in the United States are playing a musical instrument at 8:00 PM on a Thursday evening?

Estimation 8 (extra credit): The dynamic range of the human eye:  Light actually comes in bunches called photons.  The smallest flash of light we can see (when our eyes are completely dark-adapted) is seven photons, about 2.5 * 10^(-18) J of energy, in 1/10 of second.  We can estimate the largest amount of light we can tolerate as 10 times less intense than the sun.  About 1000 W/m^2 reaches us from the sun.  a) calculate how much energy from light would enter one eye in 1/10 second from the sun if you looked right at it  (are your pupils large or tiny when you do this?); b) what is the ratio of this energy to the energy of 7 photons (this is the dynamic range of the eye)?

Estimation 9 (Extra credit): Approximately 50 Americans have been killed in the first two weeks of war in Iraq.  Approximately 40,000 Americans are killed by cars and trucks each year.  Approximately 400,000 Americans are killed by tobacco-related causes each year.  a) How much time does it take for  cars and trucks to kill 50 Americans (give your answer in minutes, hours or days, whichever is most reasonable)?  b) How much time does it take for  tobacco to kill 50 Americans (give your answer in minutes, hours or days, whichever is most reasonable)?

Estimation 10 (Extra credit): If all the pizza boxes from all the pizza that ODU students consume in 1 year are saved and spread out evenly  on Foreman Field, how many layers will they make?   A football field is approximately 50 m by 100 m.

Note on estimation questions:  These questions are intended to help give you a feel for numbers and for estimating unknown quantities. There will usually be some number that is not supplied.  For example, in Estimation 1, you will need to supply the area of the front of your body.  Because we are estimating, we are looking for approximate answers.  This means that I usually want at most one significant digit in your answer.  The order of magnitude (power of ten) is much more important.  This means that if your answer is 678234, you should write 7*10^5.  7 is the significant digit and 5 is the order of magnitude.