Review 1.This is the point that all motion will be measured relative to. A. Position B. Reference C. Displacement D. Distance.

Review

1. This is the point that all motion will be measured relative to.

A. Position

B. Reference

C. Displacement

D. Distance

Review2. A point some distance and

direction from my reference point.

A.Position

B.Reference

C.Displacement

D.Distance

Review

3.The change in position.

A.Position

B.Reference

C.Displacement

D.Distance

Review

4.The total distance traveled.

A.Position

B.Reference

C.Displacement

D.Distance

Average SpeedDef: Total distance

covered divided by the total time

Path does not matter for speed!

What is the average speed of the car over

5 sec?Total distance/total time

60m/5sec = 12m/sec

Speed of a Car

0

20

40

60

80

100

0 sec 1 sec 2 sec 3 sec 4 sec 5 sec

Time

Dista

nce

VelocityDef: the speed of an object in a certain direction–Vector quantity–Units: m/s–Slope of the position vs. time graph–Symbol: V

Example: 100mph to the East

If the speed or direction changes, the velocity changes

Where is the car moving with the greatest velocity? (time frame)

Velocity of a Car

0

20

40

60

80

100

0 sec 1 sec 2 sec 3 sec 4 sec 5 sec

Time

Po

siti

on

Speed vs. Velocity

Speed

Scalar quantity

Unit: m/s

Slope of the distance vs. time graph

Symbol: s

Velocity

Vector quantity

Unit: m/s

Slope of the position vs. time graph

Symbol: v

Instantaneous Velocity

Def: the velocity of an object at a particular moment

(snap shot)

Example: the speed on the speedometer, and your direction

Velocity of a Car

0

20

40

60

80

100

0 sec 1 sec 2 sec 3 sec 4 sec 5 sec

Time

Posit

ion

QuestionsWhat is the

instantaneous

velocity of the car

at 3.5 sec?

What is the

average velocity of

the car over 4 sec?

QuestionsA: Speed B: Velocity C: Both

1. Depends on time, distance, and direction

2. Only depends on time and distance3. Has the units m/s4. Can be found using the position vs.

time graph5. Can be found using the distance vs.

time graph

Formula:

V

1=

d

t

Speed or Velocity (m/s)

Distance (m)

Time (s)

Calculating Speed or Velocity

S

1=

d

t

4-Step Approach to solving problems

Step 1 Read the problem, list the variables… what are you trying to find?

Step 2 Write the formula

Step 4 Write answer with correct units!

Step 3 Plug-n-Chug, substitute numbers into the formula and solve

Class PracticeWhat is the speed of an electric scooter that travels 20 meters in 2 seconds?

A ball is thrown so that it travels 120 meters in 8 seconds. How fast did it travel?

Class Practice

If a girl walks at a rate of 2 m/s, how long will she take to walk 100 meters?

A motorcycle travels at 25 m/s for 10 minutes (600 s). How far does it travel?

1. A Cheetah runs 120 meters in 2 seconds. What is its speed?

2. Turtles walk at a speed of 20 meters per hour. How long does it take a turtle to travel 10 meters?

3. Your bowling ball is rolling 2.5 m/s toward the pins. How long does it take to travel 12 m?

4. If it takes 5 minutes to drive to the store at 35 mph (miles per hour), how far away is the store?

Independent Practice / Exit Ticket

Mindy drives 55 mph for 30 minutes and then drives 65 mph for 2 hours. How far does she drive?

If Jim travels 13 km in 8 minutes, and Sarah travels 24 km in 17 minutes, who is going faster?