| Energy & Forces - Forces & their effects - Friction & Air Resistance - G16 |
  Teacher's Guide
EF-C3.2 |
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1. It may help the children to think of some times when they can slide their feet easily on a surface e.g. when ground is icy, when they are on wet grass, when they have roller skates on etc. and when they find it harder to slide their feet e.g. on carpet, rough tarmac etc. What is it that makes the difference? |
| 2. An alternative investigation can be done with a few different shoes. Choose shoes with rough soles and smooth soles. Find as many different surfaces as possible to try out the shoes on. Work out a way of giving each shoe the same amount of ‘push’ and measure how far each goes on each surface. Alternatively use a simple force meter (available from educational science suppliers) to measure the amount of ‘push’ needed to move each shoe on each surface. Draw up a table of results and draw conclusions. |
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3. It is easier to do this on a small scale using a plain wooden block. Use a plain wooden slope to slide the block down onto the surface to be tested. If using lubricant such as oil, water or washing-up liquid try it out on a tray, plastic or tin-foil covered area that can contain any spills or be disposed of afterwards.
Aerosol furniture polish makes a good lubricant between wooden surfaces. Apply, allow to dry, then polish to make low friction surface. Useful rollers can be made from felt pens or pencils. Worksheet C17 (G) can be used to record this investigation. |
