Exploring Friction

I was inspired to make this activity after watching how interested the children are in rolling vehicles down slopes during their block play.  I wanted to extend this further with a science activity that could be returned to over time as understanding and knowledge of friction built up.

In the basket there are two chocks to place the planks against; two because I think the children might then explore how the angle of the planks (i.e. stacking two chocks) affects the movement of the vehicles.  There are also seven planks in all.  one is plain wood, one covered in a carpet sample that I begged from the local carpet fitters, one covered in rough sandpaper, one covered in plastic made from laminating coloured paper, one covered in wool from a jumper, one covered in bubble wrap and the last covered in textured wallpaper!  I chose these as they are a range of different materials and different textures and will challenge the children's assumptions about surfaces and textures.

To make this activity you will need:

• 7 planks of wood cut to the length that you require (offcuts from DIY will do nicely!)
• 6 different materials to fix to the planks (I left one as wood!)
• A glue gun and staple gun (tacks and a hammer would do also!)
• A stanley knife and heavy duty scissors.
• Sandpaper or an orbital/belt sander.
• Two wood 'chocks'.
• One or more small vehicles with freely moving wheels.
• A basket.

Preparation:

• Cut and sand the planks and chocks so that they are smooth to the touch.
• Cut the materials to shape by drawing around the planks and cutting out the sections marked. I had to use a stanley knife for the carpet and scissors for the rest. Leave an extra edge round the wool/fabric to fold under to prevent threads and runs!
• Fix them securely to the planks using the most suitable means - I hot glued the carpet and staple gunned the other materials.
• When dried and ready, arrange in the basket and add to a suitable section of materials in your learning area.... in a Montessori classroom this may be the cultural area but equally alongside the blocks is a valid place to encourage exploration and experimentation!

Introducing it to a child:

• Wait to see if the child/ren notice the basket, if they do and start to ask questions or explore then join them and explain that the planks are to roll the vehicles down and they can be propped up on the chocks (show them if you need to).
• Encourage the child to explore and use all of the planks, talk about what the surface feels like; introduce new descriptive vocabulary such as bumpy, rough, smooth, shiny, bobbly etc. 
• If you feel it is appropriate for that child, draw attention to the effect that the different textures have on the car; you could group the planks according to whether the vehicle goes fast or slow down them, then talk about why the child thinks that happens. Ask the child to predict what they think will happen for a particular plank if they have noticed that some are slower and dome are faster.
• Don't automatically correct the child if they propose an incorrect theory, but talk about it with them and explore why they think that - you might well be surprised at the logic behind something and it isn't always helpful to override that and give instruction on the 'correct' science behind friction.  At this stage it is important to nurture positive tendencies for scientific exploration and the child will eventually when they are older discover and learn all the theories of forces, for now wonder, questioning and testing are enough!

Just so you know what you're talking about....... friction is a force that affects all types of movement on earth. When two surfaces come into contact (here the surface and the vehicle wheels) there is friction between them - the greater the friction, the greater the grip between the surfaces and the more resistance to movement. A real-life example is flat-soled pumps versus ridge-soled walking shoes; on an icy path the ridge soled shoes have the greater friction and therefore resist movement and prevent you slipping!