physics 1070
DESCRIPTION
Lecture 1TRANSCRIPT
Online Resources Lectures (password)
http://www.physics.umanitoba.ca/~mammei/Teaching/1070/Lectures/
WileyPlus (instructions on following slides)
https://www.wileyplus.com/WileyCDA/Section/Fundamentals-of-Physics-Extended-9th-Edition.id-402894.html
Student Companion Site http://bcs.wiley.com/he-bcs/Books?action=index&itemId=0470469080&bcsId=5586
Course website (password)
http://www.physics.umanitoba.ca/undergraduate/phys1070/
Wednesday, January 8, 2014 1
WileyPlus If you purchased a new textbook in the bookstore, it came with a WileyPlus
access code (if you have an account from a previous PHYS 1050 or 1070 class, you can use the old login, if you have switched from 1020/1030, please contact me ([email protected]))
Go to https://www.wileyplus.com/WileyCDA/Section/Fundamentals-of-Physics-Extended-9th-Edition.id-402894.html and follow the instructions for login
Once logged in, you can access problems on the "assignment" tab (note: while this is called "assignment", there is no due date and no grade will be assigned, this is strictly for voluntary practice)
Problems on our "recommended problem list” are generally listed at the top, all other end-of-chapter problems follow
Under the tab "Read, Study, and Practice" you will find an electronic version of the textbook and other resources
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3
• Turn on power switch and hold for 2 sec.
• Channel indicator will flash. • Use response buttons A-E to set the
channel posted in the classroom.
Channel indicator
Power switch
Response buttons A - E
Setting the frequency
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4
• Turn on the power switch. • Check that classroom frequency is set right. • Use response buttons A-E* to submit your answer. • When the process is complete, a histogram will be
displayed, and the correct answer highlighted • Questions and answers will be discussed in class.
* (If you want to change your response, just choose again while the question is open.)
Answering questions
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5
Practice Question
Wednesday, January 8, 2014
Which of the following describes how you spent time on PHYS 1070 since the last class?
A. I registered my i>clicker online
B. I read chapter 15 up to section 4
C. I tried the problems suggested at the end of class
D. I read the introductory section of the lab manual and I’m ready for next week’s lab
E. All of the above
po
siti
on
time
+x
0
-x
velo
city
time
+v
0
-v
Mass on a spring
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-1
0
1
0 1.5708 3.1416 4.7124
Sinusoidal functions
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ttx cos)(
tdt
tdxsin
)(
t
dt
tdx
dt
d
dt
txdcos
)(2
2
t
-1
0
1
0 1.5708 3.1416 4.7124
t
-1
0
1
0 1.5708 3.1416 4.7124
t
Sinusoidal Functions in SHM
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txtx m cos
amplitude
angular frequency
phase constant
time
position as a function of time
fT /1
Tf /22
# whole waves per s
# radians per s
)( Ttxtx What are 𝜑, 𝜔 and xm as shown in the plot, assuming a cosine function? A. 0 rad, 𝜋 rad/s, 1m B. 0 rad, 1 rad/s, 1m C. 0 rad, 1 rad/s, 2m D. 𝜋/2 rad, 0 rad/s, 1m E. 𝜋/2 rad, 1 rad/s, 2m
-1
0
1
0 1.5708 3.1416 4.7124
t(s)
x(m
)
3602
2
90 180
2
3
270 360
2
Sinusoidal Functions in SHM
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txtx m cos
amplitude
angular frequency
phase constant
time
position as a function of time
fT /1
Tf /22
# whole waves per s
# radians per s
3602
txdt
tdxtv m sin
)(cos 22
2
2
txtxdt
txd
dt
tdvta m
)(2 txtaF )(txF SHM
kxF Hooke’s Law
spring constant
2mk
Question
Wednesday, January 8, 2014 10
15.2.1. Object A is attached to ideal spring A and is moving in
simple harmonic motion. Object B is attached to ideal spring B
and is moving in simple harmonic motion. The period and the
amplitude of object B are both two times the corresponding
values for object A. How do the maximum speeds of the two
objects compare?
A. The maximum speed of A is one fourth that of object B.
B. The maximum speed of A is one half that of object B.
C. The maximum speed of A is the same as that of object B.
D. The maximum speed of A is two times that of object B.
E. The maximum speed of A is four times that of object B.
Example: mass on a spring
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mglk
“Vertical” SHM
Friday, January 10, 2014 12
txtx m cos
amplitude phase constant
time
position as a function of time
kxFs
angular frequency
spring constant
sF
gF
mgFg
x
xl
l
l
ll
0)( mglkF
mgxlkF )(
kxmgkxlk
gs FFF
x
Question
Wednesday, January 8, 2014 13
15.2.3. A steel ball is hung from a vertical ideal spring where it
oscillates in simple harmonic motion with a period T. At time t =
0 s, the ball is at its maximum displacement, A, from its
equilibrium position. In terms of the period, at what time will the
ball be at y = 0.75A?
A. 0.33T
B. 0.25T
C. 0.19T
D. 0.15T
E. 0.12T
For next time
Read sections 15.5 to 15.7
Check out oscillation web demos at
Wiley companion site
Do questions 4, 5 and 12
Do problems 4, 8, 9, 17, 18 and other suggested problems (see course website)
Contact me with questions!
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