Florida Teacher Certification Examinations (FTCE) Subject Area Practice Test

Which type of simple machine is used when a screwdriver is employed to open a can of paint?

1. Inclined plane

2. Pulley

3. Lever

4. Wedge

The correct answer is: Lever

When a screwdriver is used to open a can of paint, it operates as a type of lever. A lever consists of a rigid bar that pivots around a fixed point called a fulcrum. In the case of the screwdriver, the handle acts as the lever arm, and the area where the tip of the screwdriver engages with the can serves as the fulcrum. By applying force to the handle, the user can exert a greater force at the tip, allowing them to effectively pry the lid off the can. This mechanical advantage is a key characteristic of levers, which allow a smaller input force to generate a larger output force. In contrast, inclined planes, pulleys, and wedges serve different functions. An inclined plane helps reduce the effort needed to lift an object by allowing it to be pushed up a slope. A pulley is used to change the direction of a force, typically for lifting loads, by using wheels and a rope. A wedge transforms a force applied to its blunt end into forces perpendicular to its inclined surfaces, such as in cutting or separating materials. While these machines are indeed integral parts of physical mechanics, they do not apply specifically to the action of a screwdriver in this context.