1E03
Dr. PHYSICS W. Oko Office: ABB-150 e-mail: [e-mail] Office Hours: TBA Course web page (all sections) Course Outline: http://physwww.mcmaster.ca/PHYS1E03 Course web page (this section) I will be posting news and all lecture notes here: http://physwww.mcmaster.ca/~okon/1e03/1e03.html
Components of the course -Lectures: three per week -Labs: approximately every second week, 4 labs in the term. 15% of the final grade. -Tutorials: approximately every second week, alternating with labs. 7.5% of the final grade. -CAPA assignments, every week. 2.5% of the final grade -Two term tests. Total 25% of the final grade. -Final exam, 3 hours. 50% of the final grade.
Homework Using CAPA
There will be a CAPA assignment each week. Answers are entered into the computer The CAPA system tells you immediately whether the answer is correct, and allows you to try again. You can log on/off and keep working on an assignment as often as you like. The CAPA assignments themselves are worth 2.5% of your grade; and the tutorial quizzes are based on the same problems. You will get access to the CAPA assignments directly from Avenue. This is simpler than the procedure for other courses that use CAPA, but it means you have to get your Avenue login working (http://ave .m aste nue cm r.ca/) Read the CAPA help page before you start!
Homework Homework
Download and print the lecture notes in Power Point format from Download the my web page. Bring the notes for class and add your own notes to them during the lecture. Read the textbook, either just before or just after the lecture, and add to your notes as you read. read. We will prepare a list of suggested problems from the textbook We (posted as a file, or at the end of lectures notes). (posted You can download and print these. As we cover the material You from the textbook you should also try to do the appropriate questions from this list. questions
PHYS C 1E03 I PHYS S
I. Ele ctrostatics (4 weeks)
I I . DCC ircuits (2 weeks, plus labs) I I I . Magne tism(3 weeks) I V. Wave (3 weeks) s -includes electromagnetic waves
Introduction Introduction
How do things interact?
1) - Gravity a forcebe e m s twe n asse - holds plane in orbit, e ts tc. 1) Electromagnetism - a forcebe e charge twe n s - re sponsiblefor all fam force (e pt gravity) friction, iliar s xce norm m tic al, agne 1) Weak Nuclear Force - de of particle cay s 2) Strong Nuclear Force - holds nucle toge r i the
Electric Charge
A scalar quantity e gative Com s in positive and ne
+
F
+ -
REPEL
+
F REPEL
ATTRAC T
Units: coulom C b, and also sm st unit of charge e + 1.602 10-19 C alle ,
Electric Charge (continued)
ars : Chargeappe in naturein units of e e g: Particle e ctron le proton C harge -e +e
t rve Ne chargeis a conse d quantity: t hat is, t healge braic sumof positiveand ne gativecharge s is constant. Eg +5e = +2e= +8e -3e -6e
I nsulators: charge do NOT m s ove e glass, rubbe pape g: r, r - can becharge by rubbing, d but charge do not m s ove C onductors: (som ) charge m fre ly e s ove e e m tals, som liquids g: e e Sm e iconductors: e ctrical prope s le rtie be e insulators and twe n conductors e silicon, ge anium g: rm
Quiz
The conductor is neutral (no net charge). When a charged rod is brought close to it (without touching) the net force on the conductor will be: A) B) C) D) attractive repulsive zero it depends whether the rod is positive or negative ------
++ + +
-
C onductor
C oulom Law bs
Pointq1, q2 s charge e rt force on e othe xe s ach r:
F
q1
r
r
q2
F
12
21
qq F =k r r
1 2 12 e 2
r
is a unit ve paralle to r ctor l
9 2
m2 ke = 8.988x 10 N
(C oulom constant) bs
C
Ex1: Find the magnitude of the force between the charges +10 C and -5 C separated by 20 cm.
Exercise:
L m q (equilibrium) 30 30 q GIVEN: Identical Masses, m=1.0 gram L m Equal charges q L= 60 cm FIND: q
Quiz:
L m 2q What happens to each angle if the charge on the left is doubled, and the other one is halved? Assume mass of charges is small. A) angle increases B) angle decreases C) angle stays the same
?
?L
m q/2
(equilibrium)
Finding Re sultant forceve ctor:
q = 20 C
2
q = 40 C
4
300m m 400m m q3 = 30 C
Find: Force(ve ctor) on q3 , in C sian form arte .
q1 = 10C
solution