Physics Definitions Unit 1

Grade 11 - Physics

kinematics

the study of motion

motion

a change in an object’s location as measured by a particular observer

distance

the total length of the path travelled by an object in motion

direction

the line an object moves along from a particular starting point

scalar

a quantity that has only magnitude (size)

vector

a quantity that has magnitude (size) and direction

position

the distance and direction of an object from a reference point

displacement

the change in position of an object

vector scale diagram

a vector diagram drawn using a specific scale

directed line segment

a straight line between two points with a specific direction

average speed

the total distance travelled divided by the total time taken to travel that distance

average velocity

the total displacement, or change in position, divided by the total time for that displacement

position–time graph

a graph describing the motion of an object, with position on the vertical axis and time on the horizontal axis

slope

a measure of the steepness of a line

rise

vertical change between two points on a line

run

horizontal change between two points on a line

motion with uniform or constant velocity

motion of an object at a constant speed in a straight line

motion with non-uniform velocity

(accelerated motion) motion in which the object’s speed changes or the object does not travel in a straight line

acceleration

how quickly an object’s velocity changes over time (rate of change of velocity)

velocity–time graph

a graph describing the motion of an object, with velocity on the vertical axis and time on the horizontal axis

motion with uniform acceleration

motion in which velocity changes at a constant rate

instantaneous velocity

the velocity of an object at a specifi c instant in time

acceleration–time graph

a graph describing motion of an object, with acceleration on the vertical axis and time on the horizontal axis

acceleration due to gravity

the acceleration that occurs when an object is allowed to fall freely; close to Earth’s surface, g has a value of 9.8 m/s2

free fall

the acceleration due to gravity of an object in the absence of air resistance

terminal velocity

the velocity of an object when the force due to air resistance equals the force due to gravity on the object

resultant vector

a vector that results from adding two or more given vectors

component vectors

vectors which when added together give the original vector from which they were derived; one component is parallel to the x-axis and the other is parallel to the y-axis

projectile

an object that moves along a two-dimensional curved trajectory in response to gravity

projectile motion

the motion of a projectile under gravity

time of flight

the time taken for a projectile to complete its motion

range

the horizontal distance travelled by a projectile