Chapter 2 Linear Motion

Some basic terms... rate: a change in quantity divided by time; how fast something happens relative: in relation to something else

linear motion: motion in a straight line

speed: measure of how fast something is moving - measured in terms of a unit of distance divided by a unit of time

possible units: m/s * m/h km/h light-year/century / = “per”

Types of Speed: instantaneous speed: the speed at any instant ex. the reading of a speedometer

average speed: distance divided by time interval average speed = total distance covered time interval

velocity: speed in a given direction ex velocity: speed in a given direction ex. a car traveling north at 60 km/h v = d/t

acceleration: the rate at which velocity changes acceleration = change (D) in velocity time interval

The key word when talking about acceleration is CHANGE The key word when talking about acceleration is CHANGE!!! This change can be either positive OR negative!

Negative acceleration is sometimes called deceleration.

FREE FALL free fall: objects are only affected by gravity when falling (ignore air resistance)

elapsed time: time that has passed since the beginning of the fall

In free fall, acceleration is always 9.8 m/s2. g = 9.8 m/s2 v = gt

How fast is not the same as how far!