Pulley is a wheel with a rope that can rotate freely about its center. It changes the direction of force for lifting heavy loads. Can be made from wood, metal, or plastic materials
Physics is defined as the study of nature and applications of physical phenomena. Newton's laws of motion form the foundation of physics. The four fundamental forces unite to form the Grand Unified Theory
Pulley is a wheel on an axle enabling cable movement and power transfer. Earliest evidence found in Ancient Egypt and Mesopotamia. Hero of Alexandria identified pulley as one of six simple lifting machines
Tool is an object that modifies environment or helps accomplish tasks. First stone tools appeared 2.5 million years ago in Ethiopia. Early tools were made of stone, bone, and wood for food preparation and hunting
Lever is a simple machine consisting of a beam pivoted at a fixed fulcrum. It amplifies input force to provide greater output force through mechanical advantage. The law of the lever states that output force equals input force divided by distance from fulcrum
Six simple machines make work easier through force transfer or direction change. Modern tools are combinations of these six basic machines. Work is defined as force multiplied by distance (W = F × D)