The Cutting Edge

Have you ever wondered how a knife cuts? Here is a fun experiment for you and your residents.

Materials: Empty cardboard food box, plastic knife and modeling clay.

Process: Roll a ball from the clay. Ask residents to use the flat bottom of the empty box to cut the clay in half. Now ask residents to use the knife to cut the ball in half.

Result: The box bottom does not cut the clay because the force being applied is spread across the clay. The knife cuts the clay because the small edge of the knife concentrates the force in one area.