Introduction


In this investigation you are going to look at how we slip and fall over or why we don't.hw_pratfall_c.jpg

Friction is a force which acts between two surfaces. It is this force which stops us from slipping. You are going to look at some of the things which affect how much friction there is between two surfaces.

The investigation


You will do this experiment by placing a shoe on a surface and pulling the shoe with a Newtonmeter and measuring how much force is needed to make it slip.

You will need to choose something to change which you think will have an influence on how much force will make your shoe slip.

Thinking


You need to decide what factors will affect how much force will make a shoe slip along a surface.

Then you will need to choose one of them to investigate.

You might want to think about

  • How much weight is in the shoe
  • How much of the shoe is in contact with the surface (the surface area)
  • What is the surface made of

You will need to make sure the thing you choose to change can be measured.

Equipment


You will have this equipment available to you, but you can also ask for other things if you need them

  • Shoes - these might be yours
  • Newtonmeters - you will have a range of different sizes
  • A surface
  • A selection of masses

The experiment


You will put a shoe on a surface and pull it with increasing force until it slips. At the point of slipping you will need to measure what the force was and record this.

Then you will make a change to your variable and do the experiment again until you have a range of data.

Don't forget to repeat your experiment so that you can average your results.

You will then need to draw a graph of your results. What do your results tell you?

Conclusion


What did you find out?

How did the factor you changed affect the amount of friction? Or how did what you change affect how easy it was for your shoe to slip? How does the shape of the graph tell you this?