definition:  a change in velocity
 

        concept map:

Formula:   Final Velocity - Original Velocity
                 time it took to make the change

Example:  V_f - V_o  =   30 km/hr - 0 km/hr  =  30 km/hr  =  10km/hr
                  t                      3 seconds                     3 sec               sec
 
How would that look on a road? (distance, speed, time) the acceleration is constant
0m         10m  20m  30m  40m  50m  60m  70m  80m  90m        
0m/s      10m/s         20m/s                                             30m/s                          
car ____car______car_________________________car__________________________
0sec       1s                2s                                                   3s
Check this out Gravity - an acceleration
This guy is falling!  His original velocity was 0 m/s.  He has been falling for 5 seconds now.  Since he is falling at the rate of 9.8 m/s/s (all things fall at that rate in a vacuum) we can determine his final velocity after 5 seconds.

          V_f - V_o  =   V_f- 0 km/hr  =  9.8m/s
             t             5 seconds              s

       5s   X     V_f =  9.8 m/s   X    5s          to isolate Vf, we need to mutiply each side with 5s
                    5s             s                        
 
       5s   X    V_f  =  9.8 m/s   X    5s          divide out the numbers and unit
                    5s             s

              V_f = 9.8 m/s X 5
             V_f=  49 m/s

After 5 seconds, our skydiving has a velocity of 49 meter per second.

3.  To find acceleration subtract the _______ velocity from the ______velocity and divided by _____
 
 
 

Reading a graph

4.  You can analyze the motion of an accelerating object using a _________  vs
_______________ graph.
 

5.  You can analyze the motion of an acceleralting object using a __________  vs.  ________ graph.

Change in Direction

Look at the cars in the box.  Describe their motion.  Which one has constant speed?    Which one accelerates slowly?  Which one accelerates quickly?

\
 

Look at the velocity arrow as the ball moves around the corner.
    Although the speed does not change, the velocity does because the direction changes therefore the ball has acceleration.
The Rule of Thumb is explaining the arrow on the ball representing acceleration.
    The arrow is representing a negative acceleration when it facing the opposition direction of the motion of the ball.

 

Negative acceleration (deceleration or slowing down)  can be expressed in a couple of ways.  The actually speed for each second... or  the amount the speed from the origninal that has been lost.