Transcript Prelab Questions

Physics 131
Introduction
Instructor:
Dr. Michael Chen
Office:
P9442
Office Hour:
MWF. 10:30-11:30am; or by appointment
Email:
[email protected]
Section
D100
D200
TA
Chang Min KIM
Shaojie YIN
Lab Technician: TBA
Email
[email protected]
[email protected]
Physics 131
Introduction
Week of
Laboratory
Prelab Assignment/Quizzes
Jan. 7
Jan. 14
General Introduction, Error Analysis
Lab 1: The Simple Pendulum (8)
none
Error Analysis Assignment (5)
Jan. 21
Lab 2: DC Circuits and Measurements (6)
Prelab Questions (2)
Jan. 28
Lab 3: AC Circuits and the Oscilloscope (6)
Prelab Questions (2)
Feb. 4
Feb. 11
Feb. 18
Feb. 25
Lab 4: The Magnetic Field (8)
Reading break – no lab
Lab 4: The Magnetic Field (again)
Lab 5: Ray Optics, Reflections, and Concave
Mirrors (6)
Prelab Questions (2)
Mar. 4
Mar. 11
Mar. 18
Mar. 25
Apr. 2, 3
Apr. 8
Lab 6: Refraction and Thin Lenses (8)
Lab 7: Polarization and Colour (6)
Lab 8: Interference and Diffraction (6)
Practice for Practical Exam
Makeup Week
Practical Exam (30)
Prelab Questions (2)
Prelab Questions (2)
Prelab Questions (2)
Prelab Questions (2)
Physics 131
Introduction
Formal Report
• Lab 4: The Magnetic Field (focus on the current balance and
your measurement of m0 in particular).
• Engineering students taking ENSC 102 concurrently will have
their formal report marked by the ENSC 102 instructor.
• A draft of your report will be due at the start of class, Monday,
March 4. (Engineering students taking ENSC102 must hand in
the draft to the instructor of ENSC 102 by Friday March 8).Your
draft will be marked and feedback provided, which you will use
to polish up your report.
• The finalized report is due by Wednesday, April 3. (April 5 for
engineering students taking ENSC 102)
Physics 131
Introduction
Course Policies
• All labs must be done in your scheduled section.
• If you miss a lab, you must bring me medical documentation ASAP.
There will be a makeup week near the end of the semester.
• Prelab assignments: Due 10 minutes before the lab starts. Late prelab
assignments will not be accepted.
• Lab write-ups are due at the end of the lab. All lab write-ups must be
done in the lab notebooks.
• Late work will not be accepted.
• Do not copy data or anything else from others – hand in your own work
Physics 131
Introduction
What to do each week
1. Read the lab manual! Check other references, in particular your text!
2. Do the prelab assignment.
3. Think about what you are trying to measure and try to figure out which
issues will be important in doing the experiment.
4. Come to lab; listen to a brief lecture about the week’s material.
5. Do the experiment. You will work in pairs with the same lab partner
throughout the semester. Make sure you record all data, including
uncertainties. Make graphs and calculations as you go to guide your
experiments.
6. Use a pen to record data. Do not use a pencil! When you make a
mistake, just cross it out (one can still see the bad data). Don’t use
white-out to cover it up.
7. After taking data, finish the calculations, error analysis, and write a
short conclusion.
8. Turn in work by the end of class, i.e., 5:20 pm, sharp!
Physics 131
Introduction
Grading
Your course grade will be based on prelab assignments, the lab notebook,
the formal report and the practical exam. It is required to complete all the
labs to receive a passing grade of the course.
• Prelab Assignments: 2 marks each (except for the first assignment
which is 5 marks)
• Notebooks: 6 marks for each lab, except for Labs 1, 4 and 5, which are
8 marks each
0: No show
1: Do experiment partially with incomplete results
2–3: Do experiment with major error in method or analysis
4–5: Do experiment satisfactorily but with minor faults
6: Do experiment well
Error analysis: 2 marks (Lab 1, Lab 4 and Lab 6).
• Practical exam: 30 marks
• Formal Report: 20 marks
• Semester total: 123 marks maximum
Physics 131
Introduction
Drop-a-Ball Experiment
Measure the time it takes for a ball at rest to drop by 2.00m.
• > 3) Next drop a ball from above your shoulders, and have the students
record the time on a stop watch. Have at least 10 of them write their
times on the board in a table with column headings: Trial #, Measured
Value of t_i (sec), and Deviation d_i = x_i - <x> (sec). Comment on the
distribution and discuss the factors that contribute to this. Then have the
students calculate the average, the difference between each
measurement and the average (i.e. deviation), and the standard
deviation. Finish by showing them how to formally combine the average
and standard deviation (e.g. t = 3.60 +/- 0.09 s).
>
> 4) Before leaving tell the students to read Lab 1: The Pendulum and
do the Error Analysis Problems before coming to the lab the following
week.
>
Physics 131
Introduction
Drop-a-Ball Experiment
Measure the time it takes for a ball at
rest to drop by 2.00m.
Trial
#
Time
ti (sec)
Deviation
di=xi - <x> (sec)
Result: The time it takes for the ball to drop by 2.00 m is
t = 0.67 ± 0.05 sec
Physics 131
Introduction
Statistical Analysis: Suppose we have many
measurements, each with random errors.
Mean
30
10
(a)
Standard
Deviation
5
0
Uncertainty in
Mean
The mean and the standard deviation
describe the distribution of data
expected. These should not change as
the number of measurements is
increased.
Our estimate of the mean will improve,
so we expect the standard deviation of
the mean to get smaller as we do more
measurements.
0.4
0.5
0.6
0.7
0.8
0.9
300
10
(b)
5
0
0.4
0.5
0.6
0.7
0.8
0.9
3000
10
(c)
5
0
0.4
0.5
0.6
0.7
Time (s)
0.8
0.9
Physics 131
Introduction
To do before you come to the lab next week
• Read lab 1 (The Pendulum) of the lab manual, and
check the references if necessary.
• Do the prelab assignment.