Download Appendix III: Computer

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Class ______________
Date _________
United Christian College
Data Logging Experiment 4.4
New’s Second Law – Constant Force (Activity P08)
I. Purpose of the Experiment:
To study Newton’s Second Law: find an object’s acceleration if the force applied to the
object is increased but the object’s mass remains constant.
II. Background:
Newton described the relationship between acceleration, force, and mass as follows:
The acceleration of an object is directly proportional to and in the same direction as the net force,
and inversely proportional to the mass of the object:
F
a  net
m
a is acceleration, Fnet is net force, and m is mass.
III. Procedures:
1. Set up the experiment as shown in the diagram.
Track
Motion Sensor
Cart
Force Sensor
Mass and mass
hanger
Name _____________________
Class ______________
Date _________
2. Click “Data Studio  Library  Open Activity  Physics Labs  P08 Constant
Force.ds”.
3. Calibration of Force Sensor:
a. Click “Setup  Force Sensor  Calibration”
b. Type “0.00” in the “Value” of the part of “Low point”. Then push the “Tare” button on
a side of the force sensor. Finally, click the button “Take Reading”.
c. Type “1” in the “Value” of the part of “High point”. Use the force sensor to hang a
mass of 100 g and click the button “Take Reading” at the same time.
d. Click “ 確定” button to finish the calibration.
4. Press 'TARE' button on the trolley.
4. Click “Velocity Graph”.
5. Pull the cart toward the left end of the Track but keep the cart at least the minimum
distance from the Motion Sensor. Add 20 grams of mass to the mass hanger. Do not let
the mass hanger bump into the pulley.
6. Click “Start” button.
7. Release the cart and recording data.
8. Click “Stop
” button.
9. Make alignment on graphs:
a. Click
(Scale to fit)
b. Press the left button of the mouse and select the area that you want to obtain the slope of
the graph.
c. Click the ‘Fit’ menu button (
). Select ‘Linear’.
10. Record the slope of the graph as the “Acceleration (Measured)” in the Data Table
below.
11. Click “Force Table” and record the Mean of the forces as “Force (Mean)” in the Data
Table below.
12. Click “Experiment  Delete last data”. Repeat Steps 5 to 11 for a mass of 30 g.
Name _____________________
Class ______________
Date _________
Data Table
Item
Value
Value
0.02 kg
0.03 kg
Mass of Cart and Sensor
Mass of Hanger and Masses
Acceleration (Measured)
Acceleration (Calculated)
Force (Mean)
Force (Calculated)
IV. Questions:
1.
What is the percentage difference between the measured and calculated values of
acceleration?
Remember,
% difference 
measured  theoretical
 100%
theoretical
2.
What is the percentage difference between the measured and calculated values of force?
3.
What are some possible reasons for any differences between the measured and calculated or
theoretical values?