Logic Versus Emotion : Identify Difference Between Logic & Emotion By Mr. Sudhir Pai
Goal: be able to identify & know the difference between the 3 of these.
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Transcript of Goal: be able to identify & know the difference between the 3 of these.
8.6B: SPEED, VELOCITY, AND ACCELERATION
Goal: be able to identify & know the difference between the 3 of
these
Review of 8.6A
Balanced forces = no change of movement Object might not move Object move at a constant speed (think outer
space) Unbalanced forces = movement
The object will move in the direction of the larger force
Think football or tug of war
Review
Net Force Overall forces on an object
Same direction arrows = add
Different direction arrows = subtract
Review
Speed Triangle Distance always goes on top
Be able to solve for all 3 variables
8.6B Speed
Speed: the distance we travel divided by the time it takes to get there
Speed can be expressed in many ways: Meters/second Inches/year Km/hr Cm/decade
All of the above have the distance on top and unit of time on the bottom
What is velocity?
Velocity and speed are very similar.
Velocity is defined as: speed with direction
For velocity, you still use the speed equationBUT:You now have to include which direction the object is going
Examples of Velocity
24 miles /hr North 3 mm / second East 10 km / year Up
Notice how all of the above are speed, except they also include the direction. That’s velocity.
Velocity
Write the following in your notes. Write the letter: S if the example is speed or V if the example is velocity.
1. 60 miles per hour2. 4 inches per year East3. 12 cm per day West4. 2 meters per second
Why velocity matters?
Example: airline pilot
Speed: we only know how fast the pilot is going
Velocity: we know how fast AND we know WHERE the pilot is going
Acceleration
Acceleration is defined as the rate of change in velocity. Unit: meters per second squared (m/s2)
AKA: speeding up, slowing down, or changing direction.
MYTH: to accelerate means to go faster
TRUTH: to accelerate means you are just changing your speed OR direction
Different Accelerations
Positive Acceleration: speeding up Math: positive slope Math: positive number
Uphill graph
Negative Acceleration: slowing down Math: negative slope Math: negative number
Downhill graph
Tricky Language
Constant acceleration and constant velocity are NOT the same.
If an object’s velocity changes, the object is accelerating.
If an object’s velocity does not change, it does not accelerate, no matter how fast it is moving.
Acceleration is the RATE of change.
Graphs & Rates
Graphs are used to show the relationship between 2 variables.
Graphs are used in all jobs and careers.
Graphs can show trends, or patterns, between the two variables.
Understanding the Axis
Speed = distance OR: y (rise)time x (run)
What this means on a speed or velocity graph:
Distance will be your y axisTime will be your x axis
Understanding the Axis
How does acceleration look on a graph? Same idea.
Unit for acceleration: m/s2
Velocity is also meters per secondTime time (s)
Velocity is the y axis; time is on the x axis