PHYSICS 100 (Physics for Poets)
Spring Semester, 2007
University of Hawaii
This page provides some useful information
for Physics 100, a survey course on physics for
nonscience students. The emphasis is on
concepts and not mathematics. The class schedule,
homework assignments (and solutions) and old exams (some
without figures, sorry) can be accessed by
clicking on the appropriate link below.
Information about the course
Back-up instructor: Dr. Michael D. Jones
Grader: Christie Marie Castellanos
Final Exam: Friday, May. 11,
2:15-4:15PM in PSB 217
You will find the tentative
lecture schedule and the midterm
exam dates here.
Some other physics-related web sites:
Homework Assignment #1
due date: Jan. 17, 2007
For problem 1 remember that 1 inch = 2.54 cm.
For problem 5, make all your measurements in centimeters. Then you don't have to convert units for
problems 6 & 7.
For problems 6 & 7 use trial-and-error on your calculator to find the answers.
For problem 8, note that the oil consumption would go like
year____oil consumption (million barrels)
0 _______ 20
1 _______ 20(1.03)
2 _______ 20(1.03)(1.03) = 1(1.03)^2
3 _______ 20(1.03)(1.03)(1.03) = 20(1.03)^3
4 _______ 20(1.03)(1.03)(1.03)(1.03) = 20(1.03)^4 etc
Use your calculator to find what it is after 30 years.
For 9b the correct answer is either "much bigger," "much smaller" or
"about the same."
My solutions to assignment #1
Posted January 24, 2007
Homework Assignment #2
due date: Jan. 24, 2007
For problem 1 remember that 1 pound = 4.5 Newtons.
A calculation similar to that required for problem 5
is done in the lecture notes.
For problem 6, we didn't discuss this in class, please use your common
For problem 7a, 1st compute the time it takes Michael Jordon
to fall back to the ground from his highest point. Then add
the time it took him to get up there. (Solving d=1/2 gt^2
for t gives: t =sqrt(2d/g), where "sqrt" stands for square root.)
For problem 7b, remember what we learned from the
"shoot-the dead-white-european-male" demo.
For problem 8, note that the ruler will fall a dist=1/2 gt^2,
where t is the time interval that it is undergoing free fall.
Use the solution t=sqrt(2d/g) mentioned above (& in class).
Homework Assignment #3
due date: Jan. 31, 2007
For problem 1 use conservation of energy for
parts a, b & c. Use conservation of momentum
for part d.
For problem 3, first determine the total momentum
of the two football players. Which way does it
point? the way the UH player is headed? or in the direction
of the USC player? After they collide, the two players will
move together with the same total momentum.
My solutions to assignment #3
Posted February 6, 2007
Homework Assignment #4
due date: February 7, 2007
For problem 1c: The distance the earth travels is the
average velocity time. The Earth's starts moving with
the velocity determined in 1b, and 0.3 s later it is 0.
So the average velociy is the 1/2 the answer to 1b.
For problem 6: Use right hand rules to determine the
direction of the angular momentum vector and the direction
of the torque. The angular momentum vector has to move in
the direction of the torque. Does this mean the top will
precess towards the viewer? or away from the viewer?
For problem 7a), first figure out which way the earth has to
be rotating so that you first see the Sun in the east, and
last see it in the west. Then use the right-hand rule to
determine the direction of its angular momentum vector.
For 7b), which way does the moon have to move around the earth in
order to have the angular momentum vector associated with
this motion in the same direction as the angular momentum
vector associated with the earth's rotation. Do the same
for the sun.
For 7c): Suppose that today, the moon is in the position indicated in the
figure, you will first see the moon at some time.
Where will the moon be tomorrow? Will you first see it
earlier or later than today?
My solutions to assignment #4
Posted February 14, 2007
Homework Assignment #5
due date: Feb. 14, 2007
For problem 1a) you have to use the expression
for angular momentum: L=rp, where r is the
moment arm (radius of the Earth in this case)
and p=mv is your linear momentum.
For problem 2, first figure out how long
it takes for one complete pendulum swing
and then multiply by 50.
For problem 4, use the relation between frequency, wavelength and
the wave speed that we discussed in class.
For problem 5: if the ukulele string is 0.5m long,
what is the wavelength of the strings fundamental
frequency? When you know the wavelength, use
the frequency (given) to compute the wave speed.
(This is the speed of the wave in the string,
not of the sound wave that it produces.)
For problem 8, please make a pendulum with a string
and a weight and measure the period. To get reasonable
precision. measure the time for 10 swings and then divide by
My solutions to assignment #5
Posted February 20, 2007
Homework Assignment #6
due date: Feb. 21, 2007
For question 2 use Newton's Universal Law of Gravity.
For 3a (and 4a), take the relation for the acceleration due to gravity
here on Earth (g = G M_e/R_e^2) and modify it for the Moon (Sun).
For 3b (and 4b) remember that your weight on any planet, etc, will
be your mass times the acceleration due to gravity there.
For question 5a use Newton's Universal Law of Gravity & remember
that the distance to use now is the distance between you & the Moon.
For 5b, the percentage change is (2F/W)x100%, where F is
the answer to 5a.
For question 7 use Newton's Universal Law of Gravity & remember
that the distance to use now is the distance between you & Jupiter.
My solutions to assignment #6
Posted Mar 2, 2007
Homework Assignment 14
This assignment will ot be collected or graded. Some questions
like those on this HW sheet will appear on the final exam.