Study of 

• Energy

• Force

• Motion

• Direction

• How Fast

• Location at given time

System of objects that are not moving with respect to one another

How fast something moves is relative to the "frame of reference" chosen

Motion in relation to a frame of reference

Example:  moving train

• Platform as frame of reference - train moves by

• Inside the train as frame of reference - people not moving

Frame of reference and relative motion as the reason

• Eyes = you travelling at high speed

•Inner Ears = you're sitting still

Mismatch of info makes people sick

Stare at horizon to calm things down

Length of path between two points (like line segment length

SI Units = meters (m)

Large = kilometer (1 km = 1000 m)

Small = centimeter (1 cm = 1/100 m)

Ratio:  Distance to time

Speed = distance / time

Units = meters / second = m/s

Scalar measure (single number)

Total distance / total time

e.g. trip to New York

300 miles

4 hours

average speed = 300 miles / 4 hours = 75 mph

Speed at a given instant

e.g. - Speedometer reading

On distance vs. time plot

It is the slope of the plot

• steeper slope = faster movement

• zero slope = standing still

• negative slope = moving backwards

• Vector measurement

Speed and Direction

Change in velocity comes from change speed, direction or both

Rate that velocity changes

Acceleration = change in velocity / time

SI units = (meters / second) / seconds = 

meters / second² = m/s²

Change in velocity / time

Results from:

• Change in speed

• Change in direction

• Both

Velocity changes constantly with time

Plot of velocity vs. time = straight line

Plot of distance vs. time = parabola (t_²)

Acceleragtion = change in velocity / time

= (V_f - V_i) / time

Units:  (m/s) / s = m/s²

Don't forget to show work and to show units