Chapter 1 Section 1 Measuring Motion p. 4 – 9 NOTES
Vocabulary/Main Ideas
Details and Supporting Facts
o Using Reference Points
o Reference points are still objects that are
used to observe motion.
o Motion
o When an object changes its position over
time relative to a reference point.
o Common Reference
Points
o Nonmoving objects such as trees,
buildings, and the Earth are common
reference points.
o Moving objects can also be used as
reference points.
o Distance / Time = Speed
o Speed
o SI unit for speed is meters/second
o Other common units are
kilometers/hour, feet/second, and
miles/hour
o Determining Average
Speed
o Most of the time, objects do not travel at
a constant speed.
o Speed is graphed as time vs. distance
o Recognizing Speed on a
travelled
Graph
o Velocity
o Velocity is speed in a specific direction.
o Direction examples; right, left, up,
down, north, south, east, west, or
towards a specific landmark.
o Velocity changes if speed and/or direction
change
o Changing Velocity
o To find resultant velocity
o When both moving objects are
traveling in the same direction,
Pictures and Diagrams
Chapter 1 Section 1 Measuring Motion p. 4 – 9 NOTES
o Combining Velocities
o Acceleration
velocities are added.
o When objects are moving in
opposite directions, velocities are
subtracted. The resultant velocity
moves in the direction of the
larger velocity.
o The time it takes for velocity to change.
o An object accelerates if an object’s speed,
direction, or both change.
o Calculating Average
Acceleration
o Acceleration is expressed in
meters/second/second.
o Graphing acceleration
o Circular Motion:
Continuous
Acceleration
o Acceleration is expressed as time vs.
velocity
o Because objects that travel on circles are
constantly changing their direction, their
velocity is also changing. Because velocity
changes, these objects are constantly
accelerating.
o On earth we are constantly accelerating
because we change direction as we orbit
the sun.