Summary Students use their knowledge of friction and how to reduce it to move the teacher sitting on a board on a carpet. Science content Physics: Motion and Forces, Newton’s Laws, Gravity (K, 2, 6) Lessons activity is in Friction Materials Large board for teacher to sit on Floor space, ideally with different surfaces to use e.g. carpet and tile marbles, rollers or something that can go under the board and roll ice cubes Procedure Challenge: move your teacher on the board only by changing the friction Students stand around the teacher sitting on a board in the middle of the carpet. Can a student push the teacher on the board? No - too much friction between the board and the carpet. Ask for ideas for making the friction less so that we can push the teacher. Try each idea at a time to see how they affect the friction. Ideas that may come up: Use a greater force to push her, a force strong enough to overpower the force of friction. Add number of students pushing. Move the board to the less bumpy floor e.g. tile. Less friction there. Use a rolling shape - wheels, rollers or marbles - add them under the board, to reduce friction. (Hold on! They dramatically reduce the friction) Use a lubricant - add something slippery (ice, or oil, or bubble mix) - ice works well. Notes For a class that did not previously study reducing friction using rolling surfaces, we focused on the different floor types for reducing friction under the board. Students guessed what would happen when marbles were added, then we discussed why they reduced the friction. Grades taught Gr K Gr 1 Gr 2
