Physics Vocabulary Flashcards

Flashcards covering terms and definitions from Chapters 3, 4, and 5.

Mass

The amount of matter in a body; a scalar quantity measured in kilograms.

Weight

The gravitational force acting on a body; a vector quantity calculated by W = mg.

Gravitational Field Strength (g)

The force acting per unit mass at a point in a gravitational field.

Inertia

The tendency of an object to resist changes to its state of motion.

Free Fall

Motion under the influence of gravity only, with constant acceleration.

Resultant Force

The single force that has the same effect as all the forces acting on an object combined.

Newton’s First Law

An object remains at rest or moves at a constant speed in a straight line unless acted on by an unbalanced force.

Newton’s Second Law

When a resultant force acts on a mass, it causes acceleration; Formula: F = ma.

Newton’s Third Law

For every action, there is an equal and opposite reaction.

Balanced Forces

Forces that are equal in magnitude and opposite in direction, resulting in no acceleration.

Unbalanced Forces

Forces that are not equal and opposite, resulting in acceleration.

Friction

A force that opposes motion between two surfaces in contact; acts in the direction opposite to motion.

Air Resistance

A type of friction that opposes the motion of an object through air; increases with speed and surface area.

Tension

The pulling force transmitted through a string, rope, or cable when it is pulled tight.

Normal Force

The support force exerted by a surface perpendicular to the object resting on it.

Free-Body Diagram

A diagram showing all the forces acting on a single object.

Terminal Velocity

When air resistance equals weight, the object falls at a constant speed.

Force

A push or pull acting on an object; causes acceleration; Unit: Newton (N).

Moment of a Force

The turning effect of a force about a pivot; Formula: Moment = Force × Perpendicular Distance; Unit: Nm.

Pivot

The fixed point around which rotation occurs.

Principle of Moments

For an object in equilibrium: Sum of clockwise moments = Sum of anticlockwise moments.

Equilibrium

A state where there is no net force and no net moment acting on the object.

Centre of Gravity (CoG)

The point at which the entire weight of an object acts.

Stable Equilibrium

When the object returns to its original position after being slightly tilted.

Unstable Equilibrium

When the object topples after being slightly tilted.

Neutral Equilibrium

When the object stays in its new position after being slightly tilted.

Pressure

The force acting per unit area; Formula: P = F/A; Unit: Pascal (Pa).

Pascal (Pa)

SI unit of pressure; 1 Pa = 1 N/m².

Liquid Pressure

Pressure at a point in a liquid increases with depth; Formula: P = ρgh.

ρ (rho)

Density of the liquid, measured in kg/m³.

g

Gravitational field strength, usually taken as 10 N/kg in O-Levels.

h

Depth below the surface of the liquid, in meters (m).

Pascal’s Principle

A change in pressure applied to an enclosed fluid is transmitted equally to all parts of the fluid.

Hydraulic System

A device that uses Pascal’s principle to multiply force.

Manometer

A U-shaped tube used to measure the pressure difference between a gas and atmospheric pressure.

Inertia

The tendency of an object to resist changes in its state of motion.

Friction

A force that opposes motion between two surfaces in contact.

Normal Force

The support force exerted by a surface on an object resting on it.

Tension

The pulling force exerted by a string or rope.

Newton’s First Law:

An object remains at rest or moves at constant speed in a straight line unless acted on by an unbalanced force.