3-FAM-02
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Contents
Outcomes
- Pupils are to recall W = mg and use it to find the weight for a range of masses.
- To be able to estimate the weight of an unknown mass and use their forcemeter to measure the weight.
- To be able to plot a force extension graph for their spring and explore proportionality.
- Pupils use a force extension graph to find the weight of on unknown mass.
- Pupils should evaluate their force meter design.
Specification References
1.27 describe how extension varies with applied force for helical springs, metal wires and rubber bands
1.28 recall that the initial linear region of a force-extension graph is associated with Hooke’s law
1.29 associate elastic behaviour with the ability of a material to recover its original shape after the forces causing deformation have been removed.
Main Body of Lesson
Part A: Construction
- Students are to make their own force meter using acetate sheets and steel springs.
Part B: Calibrating
- They are to use the W = m g formula from 3-TAS-01 and mark the scale on their force meter with set weights.
Part C:Measuring forces using their force meter
- They can test their force meters by measuring the weight of various objects A,B and C of unknown mass.
Part D: Plotting a graph of Force vs. extension
- Students are to hang masses (again!!) on their force meter and measure the length of the spring.
- They are to record their results in a table
- Then plot a force vs. extension graph
- Lastly they hang the three original unknown masses on their force meter, measure the length of the spring, find the extension and use their graph to determine its weight.
Plenary
Homework
- There are questions on the 'Building your own forcemeter' sheet
Additional Information
Resources Required
Textbook References
- None
Website References
- None
Skills Addressed
Safety/Hazards
- When pupils are stretching springs or elastic bands, they should wear safety goggles.
- Pupils should not sit when performing this experiment as heavy masses could fall on them.
Notes
- None
