Non-Contact Forces: Magnetic, Electrical, and Gravitational Forces

Practice vocabulary flashcards covering the concepts, properties, rules, and relationships of non-contact forces, including magnetic, electrical, and gravitational forces.

Non-Contact Force

A force that pushes or pulls on an object without touching it.

Magnetic Field

An invisible region around a magnet or current-carrying conductor where magnetic force can be felt.

Magnetic Field Line Rules

Field lines move from North ($N$) to South ($S$) outside the magnet, return from South to North inside, form closed loops, never cross, and indicate a stronger field where lines are closer together.

Magnetic Pole Interactions

A rule stating that unlike poles attract each other and like poles repel each other.

Magnetic Force

An attractive (pull) or repulsive (push) force that exists between certain materials, such as magnetized iron.

Earth's Magnetic Field

An invisible field generated by swirling, liquid iron and nickel in Earth's outer core that stretches into space and shields the planet from harmful solar radiation.

Geographic vs. Magnetic Poles

Geographic poles mark the top and bottom of Earth's spin axis, whereas magnetic poles are slightly tilted and do not align with geographic poles.

Electricity

A form of energy resulting from the presence and flow of electrical charges, simply defined as the flow of electrons.

Electric Current

A flow of charge produced when electrons move from one point to another.

Static Electricity

The build-up of electric charge that occurs when two objects are rubbed together and electrons transfer from one object to the other.

Electromagnetism

The phenomenon in which an electric current flowing through a wire creates a magnetic field around it, allowing the magnetic force to be turned on, off, or made stronger.

Electrical Field

An area surrounding a charged object within which the object can exert an electrical force on another object without touching it.

Electrical Force

A force acting between electrically charged objects whose strength increases with greater charge and decreases as distance between charges increases.

Gravitational Force

A universal, always attractive non-contact force that exists between any two objects possessing mass.

Law of Universal Gravitation

A law stating that all objects in the universe attract each other through gravitational force.

Mass Proportionality to Gravity

Gravitational attraction is directly proportional to mass ($F \propto m$); doubling the mass while keeping distance ($r$) constant makes the force $2$ times stronger.

Distance Proportionality to Gravity (Inverse-Square Law)

Gravitational attraction is inversely proportional to the square of the distance ($F \propto \frac{1}{r^2}$); doubling the distance while keeping mass ($m$) constant makes the force $\frac{1}{4}$ as strong.