Chapter 9 Section 3: Acceleration

1 / 15

# Chapter 9 Section 3: Acceleration - PowerPoint PPT Presentation

Chapter 9 Section 3: Acceleration. Key concepts: What kind of motion does acceleration refer to? How is acceleration calculated? What graphs can be used to analyze the motion of an accelerating object? Key term: acceleration. What is acceleration?.

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

## PowerPoint Slideshow about 'Chapter 9 Section 3: Acceleration' - minya

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
Chapter 9 Section 3: Acceleration
• Key concepts: What kind of motion does acceleration refer to? How is acceleration calculated? What graphs can be used to analyze the motion of an accelerating object?
• Key term: acceleration
What is acceleration?
• Acceleration (OMG is that really how you spell that? Why does that look so funny right now…) is the rate at which velocity changes.
• Remember: velocity refers to speed AND direction of an object.
Acceleration: a change in velocity
• In science, acceleration refers to increasing speed, decreasing speed, or changing direction.
• Increasing speed = accelerates
• Decreasing speed = deceleration (or negative acceleration)
• Changing direction: (even an object travelling at a constant speed can be accelerating!!) a softball, for example, accelerates when it changes direction as it is hit; a runner as he/she rounds a curve accelerates even if maintaining a constant speed
Calculating acceleration
• To determine the acceleration of an object moving in a straight line, you must calculate the change in speed per unit of time.
• Acceleration = final speed – initial speed

time

Acceleration calculations continued
• SI unit for acceleration is usually m/s2
• For example: imagine an adorable plane
• The adorable plane accelerates as it takes off. Of course it does, otherwise we would never go anywhere and you would sit there on the tarmac asking your flight attendant for more tiny bags of peanuts for 8 hours and then you would get off the plane (or “deplane) in exactly the same place you started. Anyway…
It accelerates
• How do we calculate its acceleration?
• Please look at figure 7 on page 322 of your books

Do you remember the equation for acceleration?

• Its final speed is 40m/s
• It takes 5 seconds
• So, to calculate the average acceleration of the plane, you subtract the initial speed of 0 m/s (it isn’t moving when it starts) from the final speed of 40m/s, then divide the change in speed by the time, 5 seconds. Your answer is 8 m/s2
• Please attempt both math practice problems on page 323. Remember acceleration’s formula
• Acceleration = final speed – initial speed

time

How to graph acceleration
• You can use both a speed vs time graph and a distance vs time graph to analyze the motion of an acceleration object
• Look at the graph in figure 8
• How can you calculate the acceleration from this graph? Easy: calculate the slope of the line
• Rise/run = slope
What else can you tell from the graph?
• This is important: you will need to know how to read graphs for the rest of your ever-lovin’ lives!
• B/c the line is straight: the acceleration was constant
• b/c the line goes up: speed was increasing
Distance vs time graph figure 9 pg 325
• A curved line means that the object is accelerating b/c you travelled a greater distance each second than the second before it
We’re done wid dis chaptahh
• Now we commits it to memoriess