A.1 Kinematics - Key terms

study of motion

physics theories that pre-dated the paradigm shifts introduced by quantum physics and relativity

unchanging

size

quantities that have only magnitude (no direction)

a quantity that has both magnitude and direction

total length travelled, without consideration of directions

distance in a straight line from a fixed reference point in a specified direction

SI unit of length (fundamental)

average speed = distance travelled/time taken, instantaneous speed is determined over a very short time interval, during which it is assumed that the speed does not change

the time delay between an event occurring and a response, for example, the delay that occurs when using a stopwatch

an electrical component that responds to a change in a physical property with a corresponding change in an electrical property (usually resistance), also called a transducer

electronic sensor used to detect motion when an object interrupts a beam of light

SI unit of time (fundamental)

stays stationary in the same position

the galaxy in which our solar system is located

rate of change of position

rate of change of velocity with time, acceleration is a vector quantity

term commonly used to describe a decreasing speed

one which produces a straight line graph

the rate at which one physical quantity changes in response to changes in another physical quantity, commonly, for an y-x graph, gradient = Δy / Δx

mathematical process used to determine the area under a graph

electronic document in which data is arranged in rows and columns of a grid, and can be manipulated and used in calculations

branch of mathematics which deals with continuous change

mathematically determine an equation for a rate of change

equations that can be used to make calculations about objects that are moving with uniform acceleration

resistive force opposing the motion of an object through air, a type of drag force

acceleration of a mass falling freely towards earth, on, or near the earth’s surface, g = 9.8 ≈ 10 m/s², also called acceleration of free fall

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

too small to be significant

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

to express a single vector as components (usually two components which are perpendicular to each other)

apparatus used for observing rapid motions, it produces regular flashes of light at an appropriate frequency chosen by the user

path followed by a projectile

in the shape of a parabola, the trajectory of a projectile is parabolic in a gravitational field if air resistance is negligible

horizontal distance travelled before impact with the ground

collision involving relatively large forces over a short time

formation of new ideas that are not related to direct sense perception or experimental results

immediate understanding, without reasoning

stimulation (usually to be creative)

force(s) opposing motion through a fluid; sometimes called fluid resistance

liquid or gas

force(s) opposing motion through a fluid; sometimes called drag

the greatest downards speed of a falling object that is experiencing resistive forces (for example, air resistance), it occurs when the object’s weight is equal to the sum of resistive forces (+ upthrust)

analysis of motion by freeze-frame or slow-motion video replay

an experiment that is carried out in the mind, rather than actually being done, normally because it is otherwise impossible