Measuring Motion Chapter 1 Section 1

Observing motion by using a reference point Reference point – an object that appears to be stationary or mobile. An object used to compare another object in motion. Reference direction – Used to describe the direction of an object’s motion. Up, down, north, south, east and west Motion – an object’s change in position relative to a reference point.

Speed Depends on Distance and Time Speed – is the distance traveled by an object divided by time taken to travel that distance The SI unit for measuring speed is meters per second (m/s), or kilometers per hour km/h.

Determining Average Speed Most of the time objects do not travel at a constant speed. It is useful to calculate average speed. Average speed = total distance total time

Let’s Graph IT!

Velocity – Direction matters Velocity – the speed of an object in a particular direction. Velocity must include a reference direction.

Velocity Changes Velocity changes only if one of the following two factors that make up velocity changes Speed Direction Constant velocity is motion in a straight line.