How do you observe friction when you erase a pencil mark?

When you erase a pencil mark, you are observing the effects of friction between the eraser and the paper. Friction is the force that resists the motion of two surfaces sliding against each other. As you move the eraser back and forth over the pencil mark, the friction between the eraser and the paper causes the graphite particles from the pencil mark to stick to the eraser and be lifted off the paper. This process demonstrates how friction can be used to remove unwanted marks or materials from a surface.