Friction produces heat. Friction on wheels can be reduced by using lubricants such as oil, grease, or glycerin. Using smoother surfaces also reduces friction. Increase friction by using uneven or rough surfaces to generate greater pressure. Objects moved on smooth surfaces generate less friction than objects moved on rough surfaces.
Friction increases the amount of force needed to move an object.
We will do some activities that teach us more about friction. Have students increase friction experimentally by lubricating or sanding a surface to make it smoother. Bearings or wheels can also be used to decrease friction. Use a spring scale and a toy truck to measure the force Present several surfaces, such as sandpaper, plastics, tile, or concrete. Have students predict whether the surface will create more or less friction than a table top.