# Concept: Force: 6

### Master Concepts List ## Concept: Force

Force is the capacity to cause physical change via energy. Applied Concept: Force can be an influence that, if applied to an object, results its acceleration. It can also cause elastic deformation, torsion, and other physical effects to an object.

### Related Concepts

Gravity - Gravity is most commonly thought of as the agency that gives objects weight. Applied Concept: Gravity is a natural phenomenon and one of those fundamental forces by which all objects with mass attract each other. It is responsible for keeping the earth and other planets in orbit around the sun and for keeping people on the earth.

Weight - Weight is the heaviness of an object. Applied Concept: Weight can be defined as either the actual (physical) or apparent (visual) heaviness of an object or shape. Apparent weight is the illusion of weight–or heaviness–created by a shape or object.

Mass - Mass can be defined as the quantity of matter that an object contains. Mass refers to the degree of volume and density of a material. Applied Concept: Steel, for example, has more mass than and equal volume of Styrofoam–steel is a dense material and Styrofoam is mostly air. Typically, the more mass something has, the heavier it is.

Balance - Balance is the stability produced by the even distribution of weight. Applied Concept: Balance may either be true physical equilibrium–where the physical forces (like gravity) acting on an object are stable–or it can be an applied visual principle. Visual balance refers to the way elements of a design or object are arranged to create a feeling of stability.

Compressive force

• Compression/expansion - Compression is the act of pressing together or forcing into less space—constricting or squeezing. Applied Concept: A vise squeezing together two pieces of wood is also acting as a compressive force. Expansion is the act of increasing in dimensions, volume, scope, or inclusiveness; enlargement, extension, spread. Applied Concept: Expansion can be the increase in length or volume of a material, or a body, caused by temperature, moisture, or other environmental condition. Blowing up a balloon is a form of expansion.

• Elasticity/rigidity - Elasticity the capability of an object or material to recover its size and shape after deformation. The term elasticity refers to the manner in which solid materials respond to stress. Applied Concept: Something that is elastic-or has high ‘elasticity’-is capable of being easily stretched or expanded and then resuming its former shape. Most materials—other than rubber, for instance—are only elastic under relatively small deformations. Rigidity is that property of an object or material which resists a change in physical shape.

• Density - Density is a ratio of weight to volume. Applied Concept: Though 2’ diameter spheres of steel and cotton may occupy the same volume, since the steel is a denser material its sphere will have more weight.

Tensile force
• Tension - Tension is when something is in the state of being stretched or bent.

• Torsion - Torsion is a turning or twisting force.

• Stress and release - Stress and release is the relationship between applying a force and easing/lessening a force.

• Equilibrium - Equilibrium is a stable state. It is usually characterized by the cancellation of all forces by equal opposing forces.

Energetic Force
• Light - Light is a product of energy that is visible to the human eye. Applied Concept: The most common source of light is thermal energy. Light sources include the sun, incandescent bulbs, and flame.

• Potential energy - Potential energy (PE) is energy stored in a physical system; this energy can be released or converted into other forms of energy.
Elastic - Elastic PE is the potential energy of an elastic object that is deformed under tension or compression. Applied Concept: An example of Elastic PE is a pulled bow or loaded catapult.

Electrical - Electrical PE is the potential energy of a stored electrical charge. Applied Concept: Most forms of Electrical PE occur at the atomic level.

Thermal - Thermal PE is the potential energy of a system to release heat. Applied Concept: Most forms of Thermal PE are generated by movement at the atomic level.

Gravitational - Gravitational PE is the energy stored in an object as the result of its vertical position. The higher the vertical position of an object, the greater the Gravitational PE. Applied Concept: An example of Gravitational PE is someone preparing to drop a ball.

Chemical - Chemical PE is the potential energy of a chemical that could be transformed into another form of energy by a chemical reaction. Applied Concept: An example of releasing Chemical PE is burning fuel to generate heat.

• Entropy - Entropy is the tendency to evolve to a state of uniformity. Entropy is loosely referred to a breakdown of a system. Applied Concept: Examples of Entropy include–melting ice (change of temperature, until of the water equals the temperature of the room); shuffling a new card deck (change of organization, until the cards are randomly distributed); spraying air freshener (change of concentration, until the entire room smells the same).

• Friction - Friction is the force that resists motion when one object is rubbed against another. Friction always opposes movement. Applied Concept: If you were to hit a hockey puck across ice it would travel further than hitting a hockey puck across asphalt, due to ice having much less friction than asphalt.