Acceleration
Download
1 / 15

Acceleration - PowerPoint PPT Presentation


  • 306 Views
  • Updated On :

Acceleration. Change in Velocity. 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.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Acceleration' - jaden


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Change in velocity
Change in Velocity

  • 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

Acceleration= final velocity- starting velocity

time

Change in velocity = final – starting velocity velocity

Acceleration= change in velocity

time


Acceleration

A car traveling at 60 mph accelerates to

90 mph in 3 seconds. What is the

car’s acceleration?

Velocity(final) - Velocity(original)

=

Acceleration

time

90 mph - 60 mph

=

3 seconds

30 mph

=

3 seconds

=

10 mph/second


Acceleration

Positive acceleration

Negative acceleration


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?

Velocity(final) - Velocity(original)

=

Acceleration

time

0 mph - 60 mph

=

6 seconds

- 60 mph

=

6 seconds

=

- 10 miles per hour per second


Acceleration

- A constant acceleration produces a straight line or linear slope (rise/run). - The slope of a non-linear velocity-time graph (rise/run) will predict an objects instantaneous acceleration. a = v/t


Free fall
Free fall linear slope (rise/run).

  • The constant acceleration of an object moving only under the force of gravity is "g".

  • The acceleration caused by gravity is 10 m/s2

  • If there was no air, all objects would fall at the same speed

  • Doesn’t depend on mass

  • After 1 second falling at 10 m/s

  • After 2 seconds 20 m/s

  • 3 seconds 30 m/s


Galileo
Galileo linear slope (rise/run).

  • 1600’s

  • Studied how things fell

  • Didn’t have a good clock

  • Rolled balls down an inclined plane

  • Found that the speed increased as it rolled down the ramp


Galileo1

t = 0 linear slope (rise/run).

t = 1 second

t = 2 seconds

t = 3 seconds

Galileo

Acceleration= change in velocity

time


Galileo2
Galileo linear slope (rise/run).

  • Same things happen when things fall

  • Didn’t drop things from Tower of Pisa


V 2 final 2gd y
v linear slope (rise/run). 2final = 2gdy

  • A final velocity can be calculated over a vertical displacement “dy" during free fall using the equation:


D y 1 2 gt 2
d linear slope (rise/run). y = 1/2 gt2

  • The vertical displacement “dy" that occurs during a specific time of free fall can be determined using the equation:

  • Or a time interval can also be determined over a specified distance of freefall using the equation:

t2 = 2dy /g


Falling
Falling linear slope (rise/run).

  • Air resistance will increase as it falls faster

  • An upward force on the object

  • Eventually gravity will balance with air resistance

  • Reaches terminal velocity - highest speed reached by a falling object.


Terminal velocity
Terminal velocity linear slope (rise/run).

  • Force of gravity is constant

  • air resistance increases as you speed up

  • until the force is equal

  • Equal forces, no acceleration

  • constant velocity terminal velocity