Force and Motion

Front

Force Noun

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[fors]

Back

Force

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A push or a pull exerted on an object that has both magnitude and direction, causing a change in motion.

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Example: A person applies a force (a push) to an object, which is shown by the arrow indicating the direction of the push.

Front

Vectors Noun

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[vek-terz]

Back

Vectors

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Physical quantities, such as force, that are fully described by having both a magnitude and a specific direction.

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Example: This image shows how vectors represent forces. The arrows (vectors) show the direction and magnitude of two forces being added together to create a larger resultant force.

Front

Newtons (N) Noun

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[noo-tuhnz]

Back

Newtons (N)

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The standard international (SI) unit of measurement for force, equivalent to one kilogram-meter per second squared (kg·m/s²).

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Example: A spring scale measures the weight (force of gravity) of an apple. The scale shows the force is approximately 1 Newton (N), the standard unit of force.

Front

System Noun

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[sis-tuhm]

Back

System

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The specific object or group of objects of interest that is being analyzed in a given physics problem or situation.

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Example: The Earth and Moon, along with the gravitational force between them, form a system where the Moon's motion (velocity) results in an orbit.

Front

External World Noun

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[ek-stur-nl wurld]

Back

External World

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Everything that surrounds a defined system and has the potential to interact with it by exerting forces upon it.

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Example: In physics, the 'external world' or 'surroundings' includes everything outside the object or 'system' being studied that can exert forces upon it.

Front

Contact Force Noun

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[kon-takt fors]

Back

Contact Force

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A force that acts on an object by direct touch when an agent from the external world makes contact with it.

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Example: A person pushing a wall is an example of a contact force, where the force is exerted only when the person's hands are touching the wall.

Front

Field Force Noun

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[feeld fors]

Back

Field Force

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A non-contact force that is exerted between objects over a distance without any physical touching, such as gravity or magnetism.

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Example: This image shows magnetic force, a type of field force, where two magnets push each other apart without touching because their similar poles repel.

Front

Gravitational Force Noun

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[grav-i-tey-shuh-nl fors]

Back

Gravitational Force

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A fundamental, attractive field force that exists between any two objects that possess mass, pulling them toward each other.

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Example: The Earth's mass creates a gravitational force that pulls all objects towards its center, as shown by the arrows.

Front

Agent Noun

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[ey-juhnt]

Back

Agent

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The specific and identifiable source or cause that is responsible for exerting a particular force on a system or object.

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Example: The person is the agent applying a force to the box, causing it to change its state of motion by pushing it across the floor.

Front

Unbalanced Force Noun

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[uhn-bal-uhnst fors]

Back

Unbalanced Force

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A condition where the net force acting on an object is not zero, resulting in a change in the object's velocity.

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Example: This diagram shows unequal forces pushing on an object. The 100 N force pushing left is greater than the 50 N force pushing right, creating an unbalanced force.