Final answer:
Contact forces require direct physical contact and include tension, friction, and normal force, while non-contact forces, such as gravity, act over a distance without physical interaction.
Step-by-step explanation:
Contact vs Non-Contact Forces
Contact forces and non-contact, or field forces, are fundamental interactions in physics that have distinct differences. Contact forces require physical contact between objects, such as when a table exerts a force on a student's forearms or the tension in a rope. Examples include tension, friction, normal force, and the force of a spring, which all arise from interatomic electric forces at the microscopic level.
Conversely, field forces, or long-distance forces, operate without direct physical contact. The gravitational force that gives an object weight is a primary example of a field force acting at a distance due to Earth's gravitational field. Other field forces include electromagnetic forces that can dominate at the human scale.
Understanding the nature of these forces is important as they play a crucial role in interactions between systems and can result in changes such as acceleration when the net force is applied to a system.