Have you ever wondered why erasers can easily remove pencil marks? The secret lies in understanding what pencil marks actually are and how erasers work through friction.
When you write with a pencil, the graphite core leaves behind tiny particles that attach to the paper's rough surface. These particles are held in place by weak adhesive forces between the graphite and paper fibers.
Erasers work through friction. When you rub an eraser against paper, the friction force generated is much stronger than the weak adhesive forces holding graphite particles to the paper surface, allowing the eraser to pick up and remove the graphite.
Watch how the erasing process works. As the eraser moves across the paper, it physically removes graphite particles, leaving a clean surface behind. The eraser itself becomes slightly dirty as it collects the graphite particles.