Here's how:

* Magnitude: A machine can multiply force, meaning it allows you to exert a smaller force to achieve a larger force output. For example, a lever or a pulley system can help you lift heavy objects with less effort.

* Direction: A machine can also change the direction of force. For example, a bicycle uses gears to change the direction of the force applied to the pedals, allowing you to propel the bike forward.

Examples of machines that change force:

* Lever: A simple machine consisting of a rigid bar that pivots around a fixed point (fulcrum).

* Pulley: A wheel with a groove that allows a rope or cable to run around it, changing the direction of the force.

* Wheel and axle: A wheel that rotates around a central shaft (axle).

* Inclined plane: A flat surface that is raised at an angle.

* Screw: A spiral ridge wrapped around a cylinder.

Important Note: While a machine can change force, it cannot create energy. The total amount of energy remains constant, but machines can make it easier to use or direct energy in a more useful way.