Chapter 10 Lesson 1 Acceleration

Chapter 10 Lesson 1 Acceleration

by anthony kaltenbach

​The big question : How do objects react to force?

​Our Key Questions:

​

• What is acceleration?

• How do you graph acceleration?​

Your goal today!​

To understand what acceleration is, how to calculate it, and what it looks like on a graph. ​

Multiple Choice

What is the "Big Question" for this Chapter?

• How do objects react to force?

• What is acceleration?

• How do you graph acceleration?​

Multiple Select

What are the "Key Questions" for this Lesson?

• How do you graph acceleration?​

• What is acceleration?

• How do objects react to force?

Multiple Select

What are your goals for this lesson?

• To understand what acceleration is.

• To know how to calculate acceleration

• To be able to recognize an acceleration graph.

• Goals? What goals?

​What is acceleraton?

​Scientists define acceleration as:

​"The rate at which velocity changes."

​

​There is more to that than what you think.

​

​Velocity is both speed & direction.

When a measurement has both direction and a magnitude (strength) it is called a "Vector" quantity.​

​If a measurement has only a magnitude it is known as a "Scalar" quantity.

​Look at the next slide for examples!!!

Multiple Choice

What is the definition for acceleration?

• the rate at which velocity changes.

• the strength of a measurement

• how fast you are going.

• how slow you are going

Multiple Select

What does a "vector quantity" have? (2 answers!)

• magnitude

• volume

• direction

• space

Multiple Choice

Acceleration is...

• a scalar quantity

• only a speed

• only a direction

• a vector quantity

​Since acceleration is a vector quantity, that means it is measured by both its MAGNITUDE and its DIRECTION!

​Magnitude is the strength or in this case the speed!!!

​Since acceleration is a vector quantity...

​If we change anything about an objects magnitude or direction, it is considered to be accelerating!

​

​Speeding up, slowing down, or changing direction are all acceleration!

Multiple Select

Which of the following means you accelerated?

• Speeding up!

• Slowing Down!

• Changing direction!

• Staying still!

​One more time!

​In science acceleration is a vector quantity, which includes both speed and direction! If you change any of that you are considered to be accelerating!

​

​Speeding up! = accelerating

​Slowing down! = accelerating

​Turning a corner! = accelerating

​

​Staying at a constant speed in the same direction... NOT ACCELERATING!

Multiple Choice

If you are riding in a car and you are slowing down...

• you are accelerating

• you are not accelerating

• you are speeding up

• you are turning

Multiple Choice

If you are going around a corner...

• you are accelerating

• you are slowing down

• you are speeding up

• you are NOT accelerating

Multiple Choice

If you are on a bike and pedaling to go faster...

• You are accelerating

• You are NOT accelerating

• You are slowing down

• You are turning

​Let's learn the formula for acceleration!

​If an object is not turning you can describe its acceleration as the rate at which its speed changes.

​ACCELERATION =

Final (ending)speed - initial (start)speed

DIVIDED by the Time

Multiple Choice

What is the acceleration formula?

• Change in time/ change in speed

• Time x speed

• Speed x Speed

• Change in speed/ time

​One more time...

​When something isn't turning you calculate its acceleration by the change in speed divided by the time.

​Let's try it...

​An airplane has a starting speed of 0 meters per second. Its final speed is 24 m/s. It took 3 seconds to complete this.

​

​24 m/s - 0 m/s = 24 m/s

​

Now divide that by the time of 3 sec

​

​24m/s / 3 sec = 8 m/s ^2

Multiple Choice

A ride falls for 3 seconds. During that time it accelerates from 0 m/s to 30 m/s. What is the average acceleration?

• 1000 m/s^2

• 3000 m/s ^2

• 10 m/s^2

• -40 m/s^2

Multiple Choice

A roller coaster accelerates from 4m/s to 22m/s in 3 seconds. What is its acceleration?

• 6 m/s^2

• 600 m/s^2

• No acceleration

• 1 m/s

Multiple Choice

An object has a staring speed of 3 m/s and an ending speed of 18 m/s.  This object took 5 seconds to do this.  What was its acceleration?

• 1 m/s^2

• 2 m/s^2

• 3 m/s^2

​You can use 2 types of graphs to analyze the motion of an accelerating object!

​A speed vs time graph!

​On a speed vs. time graph, the slope of the line corresponds to the acceleration of the objects. Objects that are accelerating (speeding up) will have a positive slope on a speed vs. time graph, while objects that are decelerating (slowing down) will have a negative slope.

​Distance vs. time graph!

​In a distance-time graph, the gradient of the line is equal to the speed of the object. The greater the gradient (and the steeper the line) the faster the object is moving.

Multiple Select

What are the 2 graphs used to show acceleration?

• Distance vs Time

• Area vs volume

• Speed vs time

• acceleration vs displacement

Multiple Choice

What is acceleration?

• Any change in speed or direction!

• Only changes in speed

• Only changes in direction

• When an object is sitting still!