Warm Up 1) - Grade 11 Physicswattgr11physics.weebly.com/uploads/8/8/6/0/8860033/sept...Warm Up 1) 2) 3) Acceleration checkout www. physicsclassroom.com Distance - a scalar quantity.

Warm Up 1)

2)

3)

Acceleration

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Distance - a scalar quantity. - "how much ground an object has covered" during its motion. - additive total of all the displacements

Displacement - a vector quantity. -"how far out of place an object is" - the object's overall change in position.

6 m

6 m

3 m3 m

Speed -is a scalar quantity. - refers to "how fast an object is moving." -speed is the rate at which an object covers distance.

Velocity -is a vector quantity. - refers to "the rate at which an object changes its position."

Average Speed Distance TraveledTime of Travel

=

Average Velocity Δ positiontime

= = displacementtime

http://phet.colorado.edu/en/simulation/moving-man

Acceleration - is a vector quantity-that is defined as the rate at which an object changes its velocity-an object is accelerating if it is changing its velocity.

Note: acceleration is not moving fast, andif the velocity isn't changing then the acceleration equals zero.

-Velocity is increasing or decreasing (Deceleration)

- same speed different direction?

Circular motion

or

Time IntervalAve. Velocity During Time Interval

Distance Traveled During Time Interval

Total Distance Traveled from 0s to End of Time Interval

0 - 1 s ~ 5 m/s ~ 5 m ~ 5 m

1 -2 s ~ 15 m/s ~ 15 m ~ 20 m

2 - 3 s ~ 25 m/s ~ 25 m ~ 45 m

3 - 4 s ~ 35 m/s ~ 35 m ~ 80 m

Determine the Average acceleration based on the following data.

Average Acceleration Δ velocitytime

= = vf - vi

time

Units: (m/s)/s (km/hr)/s(mi/hr)/s

Determining Average Acceleration From a (v vs t) Graph

Direction of Acceleration

Depends on:

-is the object slowing down or speeding up,-is the object going left or right (+ve or -ve)

Rule of Thumb

If the object is slowing down then the acceleration is opposite to the direction of the velocity.

Compare the Velocities and Accelerations from the Graphs (v vs t)

Page 41

Is this train accelerating?

Special Case: Acceleration as a result of changing directions.

An object can move with constant speed and still be accelerating.

An object moving on a curve (and therefore changing direction) is accelerating.

Pages 33-41 in blue workbook

Pages 7 - 10 in yellow workbook