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INSTRUCTOR INFO: Beta
Keramati Sept.
1, 2 Sept.
15, 16 Sept.
22, 23 Sept.
29, 30 Oct. 6,
7 October 13 October
20, 21 October
27, 28 November
3, 4 November
10, 11 December
1, 2 December
9
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NEWTON’S SECOND LAW
When the system is at rest,
the hanging mass does not have any acceleration. This means the tension force must be equal
to the weight. When the system is
released, the hanging mass accelerates downward. Now the net force must be downward. Since the weight did not change, the
tension force now must be less than the weight to result in a downward
acceleration. PROJECTILE MOTION In order to analyze projectile motion we have to break it up into two parts – horizontal part, and vertical part. Similarly, to draw motion diagram for a projectile, we must draw two sets of diagrams and separate the horizontal motion from the vertical motion. Consider the case where a ball is shot horizontally. The motion diagrams look like this:
If the ball is projected at an angle above horizontal, then the ball initially goes up and then comes back down. To show this, we draw the motion diagrams as following:
REPRESENTATIONS OF MOTION There are only two types of motion that we study in detail in this course- (1) motion with constant velocity, and (2) motion with constant acceleration. You must know the shapes of the graphs of position vs time, velocity vs time, and acceleration vs time for these two types of motion in various circumstances. The lab was designed to help you explore these graphical features. I used the same set up you used to generate the following graphs. Please note the shape of each graph and make sure you know how to interpret it.
KINEMATICS GRAPHS These are the movies of the fan cart slowing down and speeding up in positive and negative directions. SloAway SpeedTo SloToward SpeedAway From each movie you can take data and plot a graph of position vs time. The modeling feature of the player allows you to curve-fit the data points. To begin collecting data, click on the dot on the left side to “view data points”, then track the motion of the cart by clicking the red dot on the cart with the target. Click the ruler on the left to “set the scale”. To curve-fit the data points, click on “M” on the right side of the screen and choose “Quad” for a quadratic function ( WRITING LAB REPORTS Depending on the nature of the experiment and the amount of time available, students will either write a complete lab report, or answer specific questions in a hand-out. A complete lab report must be written in the format outlined below.
Name
Partners
Date Title of the
Experiment Introduction
Body ·
Raw data presented in an organized fashion
in a data table and accompanied by appropriate units. ·
Calculations. ·
Units and uncertainties must be carried
through all calculations. ·
All uncertainty calculations must be
included in detail. ·
A clear record of your thought
process. This should include an interpretation
of what you calculated. Graphs and other presentations and analysis of
data. Conclusion Please keep in mind that a good lab report is written such that another person can use it to reproduce the experiment and get the same results. Keep your report concise (you don’t need to write pages after pages. Make an effort to write efficiently) and complete (be sure to include all relevant information to convey clearly what you did, how you did it, and what it means). This sample lab report illustrates the format that I expect to see in your reports. EVALUATION AND GRADING OF LAB
REPORTS Lab reports are submitted for evaluation at the end of each lab. I will read your report and if necessary give you suggestions for improvement without assigning a grade. You will resubmit your report with corrections. The corrected report will receive a grade. GUIDELINES FOR MAKING
CORRECTIONS TO LAB REPORTS 1. Do not erase or change the original report. 2. Use a different color to make small corrections (units, significant figures, etc.) on the original report. 3. More extensive corrections (rewriting a paragraph, redoing calculations, etc.) should be done on a separate sheet of paper and attached to the original report. 4. Place all your completed reports in a folder with pockets and turn them in by the dates indicated below. DATES TO REMEMBER Tuesday, Sept. 20 à turn in corrected reports
from Sept.1 to Sept. 16 Tuesday, Oct. 11 à turn in corrected reports from Sept. 22 to Oct. 7 Thursday, Oct. 13 à Midterm
Exam 5:00pm to 7:00pm Tuesday, Nov. 8
à
turn in corrected reports from Oct. 20 to Nov. 4 Tuesday, Dec. 6 à turn in corrected reports from Nov. 10 to Dec. 2 Tursday, Dec. 8 à Final Exam 5:00pm to 7:00pm |
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