Chapter 8: Forces Practice Flashcards

This flashcard set covers the vocabulary and key concepts from Chapter 8 on Forces, including types of contact and non-contact forces, measurements, and historical scientific contributors.

Force

A push, pull, or twist in a specific direction.

Push

To exert a force towards something.

Pull

To exert a force away from something.

Newton (N)

The unit of force; one newton is roughly equal to the force you need to keep a $102\,g$ apple from falling.

Force meter

A piece of equipment, such as a spring balance or newton meter, that measures force in newtons ($N$).

Mass

The amount of substance in an object, measured in grams ($g$) or kilograms ($kg$); it remains the same everywhere in the universe.

Weight

The force of gravity on an object; it is measured in newtons ($N$) and changes depending on mass and the strength of gravity at a location.

Force arrow diagram

A drawing showing the direction and size of forces acting on an object using arrows.

Balanced forces

Forces of the same size but acting in opposite directions; they result in no change in an object's motion.

Unbalanced forces

A combination of one or more forces that has an overall effect and changes an object's motion, such as its speed or direction.

Normal force

The force that prevents solid objects from passing through each other, sometimes called the support force.

Buoyancy

The upward force experienced by an object that is partially or fully submerged in a liquid or a gas.

Net force

The sum of all forces acting on an object; a non-zero net force results in unbalanced forces.

Friction

A contact force opposing motion due to the interaction between two surfaces rubbing together.

Air resistance

The frictional force of the air acting as an opposing force when an object moves through it; a common example of a drag force.

Drag

The frictional force of a liquid or gas.

Streamlined

A design intended to minimize air resistance or drag, often used for boats, aircraft, and high-speed trains.

Traction

A type of friction that allows shoes to grip the floor or car tires to move and turn.

Terminal velocity

The constant speed reached by a falling object when the force of air resistance equals the weight force.

Elastic spring force

The force exerted by a material like a spring or rubber band in the opposite direction to the force applied when it is stretched, pushed, or bent.

Impact force

A contact force that sometimes only lasts for a short time; it often changes an object's speed upon collision.

Applied force

A force that is applied to an object by another object or person.

Gravity

A non-contact force describing the apparent force of attraction between any two objects that have mass.

Magnetic force

A non-contact force between a magnet and another magnet or magnetic metal.

Electrostatic force

A non-contact force between positive and negative charges where opposite charges attract and like charges repel.

Static electricity

A build-up of electric charge on the surface of an object.

Electromagnet

A magnet made by passing electricity through a coil of wire; its magnetic field ceases when the current stops.

Mouldable

Describes a material that is soft enough to be easily shaped into a new form.

Brittle

Describes materials likely to break or snap into fragments when subjected to a large enough force.

Acceleration due to Earth's gravity

The rate at which objects fall near Earth's surface, which is approximately $9.8\,m/s^2$.

David Unaipon

A Ngarrindjeri man who used his cultural knowledge of boomerangs to conceptualize a vertical lift flying machine in 1914.

Joseph Rotblat

A physicist who withdrew from atomic bomb research for ethical reasons and was awarded the Nobel Peace Prize in 1995.

Magnetic field

The region in space around a magnet where the magnetic force can act.

Alloy

A substance composed of two or more elements, usually metals, such as steel (iron and carbon).

Tension

The force present in a wire, cable, or string when it is being stretched.