Forces and Motion | Properties of Matter

Measuring support forces

Classroom Activity for 11-14 Supporting Physics Teaching

What the Activity is for

This is a variation on the extending a spring experiment. Here the measurements are of compression and the support sheet Compression directs learners towards thinking about support forces.

What to Prepare

  • some top pan force scales (Bathroom scales will do, as will kitchen scales. If the only ones you can find are calibrated in grams and kilograms then use these but add a note to learners to remember that when a scale reads 1 kilogram it is because there is a force acting which is about 10 newton. Hence your pupils will have a conversion to do. If possible, have one top pan scale per pair of pupils or incorporate this activity into a forces circus. If you have no top pan scales then an equivalent experiment can be done by top loading the material with 1 kilogram masses.)
  • you will also need a compressible material which matches the scale of the force meter (Weak compression springs, pieces of soft foam or car-wash sponge will all be fine.)
  • rulers to measure compression
  • cardboard to spread the load evenly
  • copies of support sheet Compression (see below)

Safety note: Make sure that pupils don't get into situations where 1 kilogram (or larger) masses could fall on hands or feet.

What Happens During this Activity

The idea is that pupils will record the additional force required to deform the foam, spring or sponge. A piece of cardboard placed on top of the object will ensure an even force distribution.

Pupils measure the compression distance with a ruler. A table of results should be recorded and a suitable graph plotted to show the compression pattern.


Download the support sheet / student worksheet for this activity.

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