What are four simple machines found in a can opener?

1. Lever: The handle of the can opener acts as a lever, magnifying the force applied by the user.

2. Wedge: The blade of the can opener is a wedge-shaped object, which helps to pry open the can.

3. Screw: The can opener also uses a screw to pierce the lid of the can and create an opening.

4. Wheel and Axle: The wheel and axle mechanism is used to turn the cutting blade and open the can.