Rate of change of velocity with time, $$\frac{\Delta v}{\Delta t}$$  

The description of a single measurement, or the mean of a series of measurements, that is close to the correct result.

Resistive force opposing the motion of an object through air.

The number of particles in one mole of a substance.

Important constant which links microscopic molecular energies to macroscopic temperature measurements.

To put numbered divisions on a scale.

A temperature scale based on the melting point and boiling point of water.

The average position of all the mass of an object.

The energy related to the arrangement of electrons within the structure of atoms and molecules.

Constant used to represent the amount of friction between two stationary surfaces.

Constant used to represent the amount of friction between two moving surfaces.

Two (or more) objects coming together and exerting forces on each other for a short length of time.

Two parts of a vector quantity, usually perpendicular to each other.

The total energy in any isolated system remains constant. Energy cannot be created or destroyed.

The total momentum in any isolated system remains constant. The total (linear) momentum of a system is constant provided that no external forces are acting on it.

Forces that occur between surfaces which are touching each other, perpendicular to the surfaces. Select two.

Units of measurement that are defined in terms of other units.

Defined as the distance from a reference point in a specific direction. A vector quantity.

Length, a scalar quantity.

The force(s) opposing motion through a fluid.

Defined as the ration of the useful energy (or power) output from a device to the total energy (or power) input; often expressed as a percentage.

A from of energy that is stored in a material which has been deformed elastically. The energy is transferred when the material returns to its original shape: $$PE=\frac{1}{2}k\Delta x^2$$  

When a measurement is not exactly the same as the correct value.

Vertical and horizontal lines drawn through each data point on a graph to represent the uncertainties in the two values.

The ratio of force to extension for a stretched material or spring: $$k=\frac{\Delta F}{\Delta x}$$  

A location to which observations and measurements of motion are compared. For example, the speed of a car may be 10 m/s compared to the Earth's surface.

A diagram showing all the forces acting on a single object, and no others.

The motion through the air under the effects of gravity but without air resistance.

Resistive forces opposing relative motion, particularly between solid surfaces, which prevents movement.

Resistive forces opposing relative motion, particularly between solid surfaces, when objects are already in motion.

Units of measurement that are not defined as combinations of other units.

Fundamental attractive forces that act across space between all masses.

Energy that masses have because of the gravitational forces between them: $$PE=mg\Delta h$$  

Energy that is transferred from one body to another as the result of a difference in temperature.

The force needed to deform a spring is proportional to the extension (or compression): $$F=k\Delta x$$  

Defined as the product of force and the time for which the force acts. It is equal to the change of momentum.

A flat surface at an angle to the horizontal. A simple device which can be used to reduce the force needed to raise a load, sometimes called a ramp.

The value of a quantity at one particular instant (not an average value).

The total potential energy and random translational kinetic energy of the molecules of a substance.

Derived SI unit of work and energy.

A temperature scale based on absolute zero and the triple-point of water.

Measure of the mean random translation kinetic energy of one molecule of an ideal gas: $$KE=\frac{3}{2}k_BT$$  

SI unit of mass (fundamental).

The study of moving objects.

Energy of moving masses: $$KE=\frac{1}{2}mv^2$$  

A relationship that produces a straight line graph.

This describes an object that can be observed without the need for a microscope.

The property of matter which resists changes of motion.

SI unit of length (fundamental)

This describes anything which is too small to be seen with the unaided eye.

Defined as the mass of a substance which contains one mole of its defining particles.

SI unit of amount of substance (fundamental)

Defined as mass times velocity: $$\rho=mv$$  . A vector quantity.

Too small to be significant.

A derived SI unit of force.

An object will remain at rest, or continue to move in a straight line at a constant speed, unless a resultant force acts on it.

Acceleration is proportional to resultant force: $$F=ma$$  

Whenever one body exerts a force on another body, the second body exerts exactly the same force on the first body, but in the opposite direction.

Perpendicular to a surface.

When a value for a quantity is not known precisely, we can give an approximate valued by estimating a value rounded to the nearest power of ten.

In the shape of a parabola.

Defined as energy transferred/time taken ( $$P=\frac{\Delta E}{\Delta t}$$ ) or, for mechanical energies ( $$P=\frac{\Delta W}{\Delta t}$$  ).

A measurement can be described as this if a similar result would be obtained if the measurement was repeated.

An object that has been projected through the air and which then moves only under the action of the forces of gravity and air resistance.

Data describing qualities or characteristics that may be difficult to precisely measure and analyze.

Data that can either be counted or compared on a numeric scale.

Measurements of any quantity may be bigger or smaller than the correct value and are scattered around that value (for various reasons).

The distance travelled before the projectile impacts the ground.

Forces always occur in pairs and these forces are sometimes described as action and reaction.

The single vector which would have the same effect as the combination of two or more separate vectors.

The vector sum of the forces acting on an object.

A quantity which has only magnitude (no direction).

SI unit of time (fundamental).

All the digits used in data to carry meaning, whether they are before or after a decimal point.

Defined as the amount of energy needed to raise the temperature of 1 kg of a substance by 1 K: $$c=\frac{Q}{m\Delta T}$$  

Defined as distance travelled/time taken: $$v=\frac{\Delta s}{\Delta t}$$  

Readings from several measurements that are all either bigger or smaller than the correct value by the same amount.

This determines the direction of thermal energy transfer. It is a measure of the average random translational kinetic energy of the molecules of a substance.

A force which tries to stretch an object or material.

The greatest downwards speed of a falling object which is experiencing resistive forces.

Defined as the amount of energy needed to raise the temperature of something by one Kelvin.

The transfer of energy between two or more bodies at different temperatures (from hotter to colder).

A state at which an object is remaining at rest or continuing to move with constant velocity.

The range, above and below a stated value, within which we would expect any repeated measurements to fall.

Quantity which has both magnitude and direction.

Defined as rate of change of displacement with time: $$v=\frac{\Delta s}{\Delta t}$$  

Derived SI unit of power.

Gravitational force acting on a mass: $$mg$$  

Energy transfer that occurs when an object is moved with a force: $$W=Fs\cos\theta$$