catalyst

Catalyst

The equation for acceleration is

1. A lizard accelerates from 2 m/s to 10 m/s in 4 seconds. What is the lizard’s average acceleration?

2. If a Ferrari, with an initial velocity of 10 m/s, accelerates at a rate of 50 m/s/s for 3 seconds, what will its final velocity be?

3. What three things can you do to accelerate?

vf - vita=

Today’s Agenda

5 min•Catalyst

35 min•Motion Graphs and Review

5 min•Exit Slip

Motion Graphs

There are THREE types: Position vs. Time

Gives your position over a period of time. Velocity vs. Time

Gives your speed (velocity) over a period of time. Acceleration vs. Time

Gives your acceleration over a period of time.

Position vs. Time Graphs

We’ve seen these before!

Slope is velocity (or speed)

Straight lines mean constant velocity

Position vs. Time Graphs

Curved lines mean acceleration Cannot find slope

of curved lines

Position vs. Time Graphs

Horizontal (flat) lines mean no motion Constant position

Position vs. Time Graph Demonstration

http://zonalandeducation.com/mstm/physics/mechanics/kinematics/xvaVsTime/xVsTime.html

Velocity vs. Time Graphs

These are new!

Slope is acceleration

Straight lines mean constant acceleration

Velocity vs. Time Graphs

Curved lines mean changing acceleration Cannot find slope

of curved lines

Velocity vs. Time Graphs

Horizontal (flat) lines mean no acceleration or constant speed

Velocity vs. Time Graph Demonstration

http://www.physicsclassroom.com/mmedia/kinema/fs.cfm

Acceleration vs. Time Graphs

Flat lines mean constant acceleration

Everything else means nothing! (for our purposes)

The only other acceleration vs. time graph you will see is this:

Which means no acceleration

Example: No Motion

Position vs. Time

Velocity vs. Time

Acceleration vs. Time

Example: Constant Velocity

Position vs. Time

Velocity vs. Time

Acceleration vs. Time

Example: Constant Acceleration = Object is Speeding Up

Position vs. Time

Velocity vs. Time

Acceleration vs. Time

Guided Practice #1-2

Which of the objects on each graph at right is accelerating? How do you know?

Guided Practice #3

At which point is velocity (speed) the greatest?

At which point is velocity (speed) the least?

At which points is acceleration occurring?

Guided Practice #4

At which point is velocity the greatest?

At which point is velocity the least?

At which points is acceleration occurring?

Where is acceleration the least?

Today’s Agenda

5 min•Catalyst

35 min•Motion Graphs and Review

5 min•Exit Slip

Exit Slip1. What would the velocity vs. time graph look like for a car going straight on a highway at constant speed?

a. A horizontal (flat) lineb. A straight line that is

increasingc. A straight line that is

decreasingd. A curved line that is

increasing

2. What does a straight line with a positive slope mean on a velocity vs. time graph?

a. Increasing velocityb. Constant accelerationc. Constant velocityd. Both A and B

Exit Slip

3. True or false: Constant acceleration means that the object is speeding up.

5. For which graph does a horizontal (flat) line always mean that the object is motionless?

a. Position vs. timeb. Velocity vs. timec. Acceleration vs. timed. Both A and C