NCEA Science 1.1 Mechanics AS 90940 Vocabulary

Essential vocabulary terms and definitions covering motion, forces, Newton's laws, mass and weight, pressure, work, power, and energy conservation based on NCEA Science 1.1 Mechanics.

Motion

The state of objects that move from one point of space to another over time.

Stationary

The state of objects that remain at the same point of space over a period of time.

Speed

A measure of the distance travelled over the time taken ($v = \frac{d}{t}$).

Constant Speed

A condition occurring when an object travels the same amount of distance during each equal time period.

Average Speed

The speed travelled on average over an entire distance, calculated by dividing the change in distance by the change in time ($v_{\text{ave}} = \frac{\Delta d}{\Delta t}$).

Instantaneous Speed

The speed that an object is travelling at in a specific, particular moment.

Acceleration

The rate of change in velocity over time ($a_{\text{ave}} = \frac{\Delta v}{\Delta t}$), measured in metres per second per second ($\text{m}\,\text{s}^{-2}$).

Deceleration

A decrease in velocity over time, also referred to as negative acceleration.

Force

A push, pull, tug, heave, squeeze, stretch, twist, or press that can change an object's shape, movement, or velocity.

Contact Forces

Forces that require physical contact between the source of the force and the object it acts upon, such as pushes, pulls, friction, and tension.

Non-contact Forces

Forces that act on an object from a distance without physical contact, such as electrostatic, magnetic, and gravitational forces.

Thrust Force

An applied contact force requiring parts of an object (gas, liquid, or solid) to be forcefully pushed from itself against a medium.

Friction Force

A contact force opposing motion that occurs when one surface moves against another, converting kinetic energy into heat energy.

Resistance

Friction that occurs between a moving solid body and air or water.

Gravity

A non-contact attractive force acting between bodies of mass, creating a surrounding gravitational field.

Support Forces

Upward forces that act equal and opposite to an object's downward weight force when forces are balanced.

Buoyancy

An upward support force caused by a fluid that opposes the weight force of an object in that fluid.

Newton's First Law

The physical law stating that if the forces acting on an object are balanced, the object will remain stationary or continue moving at constant speed in the same direction.

Newton's Second Law

The physical law stating that if unbalanced forces act on an object, the object will accelerate in the direction of the net force ($F = m \times a$).

Terminal Velocity

The constant maximum velocity reached when the downward gravitational acceleration force on an object is matched exactly by opposing air friction.

Net Force

The resultant force produced when multiple forces interact on an object.

Mass

The amount of atoms or substance in an object, measured in kilograms ($\text{kg}$), which does not change based on location.

Weight

The downward gravitational force experienced by an object due to its mass ($F_w = m \times g$), measured in newtons ($\text{N}$).

Pressure

A measure of force applied per unit surface area ($P = \frac{F}{A}$), measured in pascals ($\text{Pa}$) or newtons per square metre ($\text{N}\,\text{m}^{-2}$).

Pascal

The standard unit of pressure, equivalent to one newton of force exerted across one square metre of surface area ($1\,\text{N}\,\text{m}^{-2}$).

Work

The energy transferred when a force applied to an object moves it over a distance ($W = F \times d$), measured in joules ($\text{J}$).

Power

A measure of work done or energy transformed over time ($P = \frac{W}{t}$), measured in watts ($\text{W}$).

Watt

The metric unit of power, equivalent to one joule of energy transformed or work completed per second ($1\,\text{J}\,\text{s}^{-1}$).

Kinetic Energy

The form of energy an object possesses due to its motion, dependent on the object's mass and velocity ($E_k = \frac{1}{2}m v^2$).

Gravitational Potential Energy

The stored energy gained by an object of mass when raised above the ground or centre of gravity against a gravitational field ($E_p = m \times g \times h$).

Law of Conservation of Energy

The fundamental principle stating that energy cannot be created or destroyed, but only transformed from one form to another.