Unit 1: Motion - Physics Vocabulary

Kinematics

Study of motion

Uniform Motion

Movement at a constant speed in a straight line

Nonuniform Motion

Movement that involves change in speed or direction or both

Scalar Quantity

Quantity that has magnitude, but no direction

Base Unit

Unit from which other units are derived or made up

Derived Unit

Unit that can be stated in terms of the seven base units

Instantaneous Speed

Speed at a particular instant

Average Speed

Total distance of travel divided by total time of travel

Vector Quantity

Quantity that has both magnitude and direction

Position

The distance and direction of an object from a reference point

Displacement

Change in position of an object in a given direction

Velocity

The rate of change of a position

Average Velocity

Change of position divided by the time interval for that change

Resultant Displacement

Vector sum of the individual displacements

Frame of Reference

Coordinate system relative to which a motion can be observed

Relative Velocity

Velocity of a body relative to a particular frame of reference

Accelerated Motion

Nonuniform motion that involves change in an object’s speed or direction or both

Uniformly Accelerated Motion

Motion that occurs when an object is travelling in a straight line changes its speed uniformly with time

Acceleration

Rate of change of velocity

Instantaneous Acceleration

Acceleration at a particular instant

Instantaneous Acceleration

Acceleration at a particular instant

Average Acceleration

Change of velocity divided by the time interval for that change

Tangent Technique

A method of determining velocity on a position-time graph by drawing a line tangent to the curve and calculating the slope

Tangent

A straight line that touches a curve at a single point and has the same slope as the curve at that point

Instantaneous Velocity

Velocity that occurs at a particular instant

Acceleration due to Gravity

The vector quantity 9.8 m/s ^2 [down], represented by the symbol \vec{g}

Terminal Speed

The maximum speed of a falling object, at which point the speed remains constant and there is no further acceleration