Year:
Form 3
Subject:
Physics (Practical)
Level:
SEC
Title:
Principle of Moments (using Datalogger)
Aim: The aim of the practical is to verify the Principle of Moments involving the use of a datalogger.
Apparatus needed:
• 2 stands and clamps,
• 1 metre ruler with a drilled hole exactly at the centre,
• 1 pivot (usually consists of a nail which can be attached to a stand and clamp),
• 1 set of masses (with hanger),
• 2 strings,
• 1 NOVA datalogger + 1 force sensor.
Diagram and pictures of the setup:
Mr Jurgen Azzopardi
Procedure to be adopted:
1. Set the apparatus as shown in the diagram and pictures.
2. The force sensor is best set (using the small switch on its side) to ±50N and usually needs to be calibrated
as follows:
• Make sure that the sensor is not touched and that it is not attached to the ruler.
• Open the Multilab software installed on the NOVA datalogger to calibrate the sensor.
• Go to Logger > Setup
o In the [Sensors] tab, press the ‘Sensor Properties’ button on the right side of input 1.
o Click the tab [Set Zero] and make sure that “Set the current reading to zero” is ticked.
o Press the ‘Reset Zero’ button and press OK.
• Click the [Rate] tab in the Setup window, and select “Manual” in the drop down menu.
• Click the [Samples] tab, and select “10” in the sample drop down menu.
• Press OK.
3. The (fixed) force sensor balances the ruler horizontally with masses hanging on the other side of the ruler.
4. Students can measure and record the distance between the pivot and the force sensor.
5. Students then record the weight of the hanging masses and measure their distance away from the pivot.
6. Using the “spreadsheet” view of the Multilab, students press the Run button to take a reading of the
force and record it (the datalogger will give a negative value for the pulling force).
7. The results can be tabulated as follows:
Anti-clockwise Moments
Weight
Distance
Moment
(N)
(m)
(Nm)
Weight
(N)
Clockwise Moments
Distance
Moment
(m)
(Nm)
8. The clockwise and anti-clockwise moments can be calculated and compared.
9. The experiment can be repeated using different masses and distances away from the pivot.
Positive features of this practical:
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•
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No trouble to balance the ruler each time the experiment is repeated.
Experiment will take less time.
Can be performed in small groups of students.
Results are rather accurate and both clockwise and anticlockwise moments will be approximately equal
(especially if taken to 1 decimal place).
The mathematical aspect of the practical is not affected.
Students will enjoy using the datalogger ☺
Mr Jurgen Azzopardi