Final answer:
An applied force occurs when a human, animal, or machine pushes, pulls, or twists an object, and it is a type of contact force.
Step-by-step explanation:
When a human, animal, or machine pushes, pulls, or twists an object, the type of force that occurs is an applied force. This is a form of contact force where direct physical contact is made to apply the force. In contrast, forces such as tension, magnetism, and gravity can either be contact or long-distance forces. Gravity is a universal force that always acts, whereas magnetism is a force that can act over a distance without direct contact.
Contact forces, such as the applied force, result from the interaction of objects touching one another and stem from interatomic electric forces at the microscopic level. Whether it is a person lifting a box or a tow truck pulling a vehicle, these scenarios all involve an applied force, which is often the result of manual or mechanical effort to move an object. Understanding forces and how they are categorized is a fundamental aspect of physics that aids in explaining a wide range of phenomena.