Final answer:
A simple machine changes the amount of force required to perform work by increasing the distance over which the force must be applied, thus giving a mechanical advantage but not altering the total amount of work done.
Step-by-step explanation:
A simple machine NEVER changes the amount of work done. What a simple machine changes is the force required to perform that work. It does this by either increasing the distance over which the force must be applied, or by changing the direction of the force, thereby making it easier to perform a task. The work done, calculated as the product of force and distance (fd), remains constant in a simple machine.
For example, using a lever can allow a person to lift a heavy object with less force than would be needed to lift it directly upward. However, they will need to move the lever through a greater distance than the direct upward lift. This is an illustration of how simple machines offer a mechanical advantage, making tasks more manageable without changing the total amount of work performed.