Transcript Acceleration PPT

 Each time you take a step you
are changing the velocity of
your body.
 You are probably most
familiar with the velocity
changes of a moving bus or
car.
 The rate at which velocity
(speed or direction) changes
occur is called acceleration.
Acceleration= final velocity- starting velocity
time
Change in velocity = final
starting
–
velocity velocity
Acceleration= change in velocity
time
A car traveling at 60 mph accelerates to
90 mph in 3 seconds. What is the
car’s acceleration?
Acceleration
=
Velocity(final) - Velocity(original)
time
=
=
90 mph - 60 mph
3 seconds
30 mph
3 seconds
= 10 mph/second
Positive
acceleration
Negative
acceleration
A car traveling at 60 mph slams on the breaks to
avoid hitting a deer. The car comes to a safe stop
6 seconds after applying the breaks. What is the
car’s acceleration?
Acceleration =
Velocity(final) - Velocity(original)
time
=
=
0 mph - 60 mph
6 seconds
- 60 mph
6 seconds
= - 10 miles per hour per second
- A constant acceleration
produces a straight line
Acceleration= change in velocity
time
t=0
t = 1 second
t = 2 seconds
t = 3 seconds
 Same things happen when things fall