Spring semester 2008, Phys1101 General Physics 1
Solutions for short quizzes will be
posted here..
Quizzes: Approximately ten 10-min Quizzes will be given,
usually on Wednesday. They consist of a couple of questions or a quantitative
problem, worth a total of 10 points Please be prepared and bring your
calculator. If you know you will not be present for a quiz, please let me know
and take it early.
Quiz
7 -solution average score 8.9
Quiz 6
solution (online quiz) average score 5.9
Average score 7.1 
Most common problems:
1.
The
centripetal force is a term used for the sum of all radial forces. Radial
forces can arise from all sorts of interactions. IN the quiz the static
friction interaction between squirrel and blade serves as the centripetal
force. Hence, in the free-body diagram, only the friction force should show up.
2.
The
speed of the squirrel can be gotten from considering distance/time. One full
circle in a time of T=6s. Hence, the speed is circumference over period.
3.
The
instantaneous velocity of the squirrel at any time points in tangential direction.
Hence, if the static friction force suddenly goes away, this velocity will be
maintained. The squirrel will move away in tangential direction. This still
means that the blade will slide out from under it in a forward direction, but
for the outside observer, the motion is tangential.
Quiz
4 alias worksheet on radial and tangential acceleration - solutions
solutions
for quiz 3 average score 6.0
The distribution shows, that 50% of the
class have understood the basic workings of projectiles motion –great!
This is for all of those who really have not
spent enough thought on this yet.
What are the most common problems?
·
The
horizontal and the vertical motion are separate sets of equations. You cannot
mix horizontal speed and vertical acceleration in the same equation, since they
do not pertain to the same direction.
·
The
speed of a particle is the magnitude of the velocity vector. If the velocity
has both, horizontal and vertical components, the speed will follow from the
Pythagorean Theorem.
·
Sketch:
If the initial velocity is given as horizontal, then there should be no initial
upward component in your drawn trajectory.
If the Wednesday
quizzes scare you, remember
·
They will be an obvious and not the most difficult
thing I can ask about something pertaining to Friday’s or Monday’s lecture.
This is really not that hard to guess. Ask yourself, what you would put on the
quiz given the stuff presented in class. Your speculation will probably be
close to what is going to be asked.
·
Practice, practice, practice. At the end of each
book chapter, there are discussion questions and example multiple choice
questions. How about those for a quick inspiration on quiz questions?
·
Solution
for Quiz 2 average score 8.3
Solution
for Quiz 1 average score 7.9
Last
modified: 5/12/2008
Maintained
by Sylke Boyd