Final answer:
Inclined planes reduce the effort needed to lift objects by extending the distance over which force is applied, keeping the work done constant. Historical usage includes moving heavy stones during the building of the Egyptian pyramids. Friction is a key factor that can affect the functioning of an inclined plane.
Step-by-step explanation:
Inclined planes are a type of simple machine that make it easier to lift objects by reducing the amount of effort force needed. When using an inclined plane, the force required to move an object upwards is less compared to lifting it vertically. However, this often means that the distance over which the force must be applied is increased, meaning the amount of work (force times distance) remains constant, assuming there is no energy loss due to friction.
Historical examples, such as the construction of the Egyptian pyramids, suggest that inclined planes were used to move heavy blocks of stone. The principle behind this is when an object rests on an inclined plane, gravity's force is divided into two components: one perpendicular to the plane and one parallel. The parallel component causes the object to accelerate down the slope, and friction opposes this motion. By adjusting the angle of the inclined plane, the component of the weight acting along the plane can be managed, thus changing the needed effort force to move the object.