1. 2-1 Describing Motion
What factors are important when describing motion?
Time
Distance

2. Speed Distance object travels in a certain amount of time
a description of motion
tells how fast an object moves

3. Calculating Speed
What two sets of data need to be collected in order to calculate speed?
Distance
Time

4. Speed Equation
Combining all of the information along with the definition of average speed the equation is

5. Where
v is average speed, units of m/s
d is distance, units of meters
t is time, units of seconds

6. a speed that stays the same and doesn’t vary Instantaneous speed
Constant speed
a speed that stays the same and doesn’t vary
Instantaneous speed
rate of motion at an exact time
look at a speedometer to find

7. average speed Most speeds aren’t constant, they vary
bike riding in the wind
passing a car
going down hill
running slower because you are tired
Use average speed-total distance divided by total time.
Unable to determine instantaneous speeds or if speed was constant

8. Velocity Velocity vs speed
If you are to out run a storm, what information would you want to know?
Velocity is a speed in a certain direction

9. Can you keep constant velocity, but change your speed?
Can you keep constant speed, but change your velocity?