Measuring MotionUnderstanding Speed,

Velocity, and Acceleration

SPEED rate at w/c an object moves

Distance (D)

Speed =

Time (T)

Type of Movement

Distance/m

Ave. Time/sec(Total Time/3)

Speed (S=d/t)

Change

Skipping 0 0 05

1015

Backwards 0 0 05

1015

Walking 0 0 05

1015

Speed walk 0 0 05

1015

CONSTANT SPEED

SPEED THAT DOES NOT CHANGE

CONSTANT SPEED

SAMPLE PROBLEM:

At what speed did a plane fly if it traveled 1760 meters in 8 seconds?

STEPS IN PROBLEM SOLVING

STEP 1. Write the formula STEP 2. Substitute given numbers and units STEP 3. Solve for the unknown.

SOLUTIONStep 1. Speed = Distance/Time

Step 2. Speed = 1760 meters/ 8sec

Step 3. Speed = 220 m/sec

SAMPLE PROBLEMS:1. A car travels 240 kilometers in 3 hours. What is the speed of the car during that time?

ANSWER: S= d/t S= 240 km/3 hr

80 Km/Hr

The speed of a cruise ship is 50 km/hr. How far will the ship travel in 14 hours?

Answer: D = ST 700 km

AVERAGE SPEED

TOTAL DISTANCE / TOTAL TIME

AVERAGE total distance traveled

SPEED time=

AVERAGE SPEED

A car travels 200 m in 10 seconds. What is the average speed of the car?

ANSWER: Ave speed= total d/total time

= 200m/10s

20 m/s

Definitions:

A change in position in a certain amount of time is __________.

__________________ is the rate at which an object moves and is determined by dividing ____________ by _____________.

_________________________ is speed that does not change.

_________________________ is calculated by dividing the total distance by the total time.

Image source: http://www.myteacherpages.com/

Type of Movement

Distance/m Speed (S=d/t)

Direction Velocity (Speed with direction)

Skipping 0 0

5

10

15

Backwards 0 0

5

10

15

Walking 0 0

5

10

15

Speed walk 0 0

5

10

15

Velocity• The speed and direction of an object’s

motion.–88 km / hr southwest

Image source: http://www.myteacherpages.com/

VELOCITYSPEED IN A GIVEN

DIRECTION

Vd

t=

direction

A bird flies south at 20 m/s.

• SPEED = 20 m/s• VELOCITY = 20 m/s south

A tropical disturbance spotted east of the Philippines was moving at 60 km per hour at a Northwesterly direction and having maximum sustained winds of 150 km/h? What is the storm’s velocity?

Given: S= 60km/h T= 10s dir= NW

1.Formula V= d/t with dir

2.Work/Answer V= 60km/h NW

CONSTANT VELOCITY

CHANGING VELOCITY

Exploring Acceleration

0m 5m 10m 15m

FinishStart

Are you speeding up, slowing down, or moving at constant velocity?

ACCELERATIONRate of change in velocity

Final velocity – Original Velocity

TimeA=

Change in velocity divided by the time during which this change occurs

A roller coaster’s velocity at the top of the hill is 10 m/s. Two seconds later it reaches the bottom of the hill with a velocity of 26 m/s. What is the acceleration of the roller coaster?

SOLUTION:

Final Velocity – Original Velocity

TimeA=

26 m/s- 10 m/s

2 s

16 m/s

2 s

A= 8 m/sec/sec

A= A=

DECELERATION

• decrease in velocity• negative acceleration• slows down

A car accelerated from 0 m/sec to 30

m/sec in 10 sec. What was the rate of acceleration?

3 m/sec/sec

A roller coaster is moving at 25 m/sec at the bottom of a hill. Three sec. later it reaches the top of the next hill, moving at 10 m/sec. What is the deceleration of the roller coaster?

- 5 m/sec/sec

Type of Movement

Distance in meters

Final Velocity(m/s)

Initial velocity

(m/s)

Time (every 5 meters)

Acceleration

Speed walk 0 0 0 0 0

5

10

15

CIRCULAR MOTION

Velocity is continuously

changing Object is

accelerating even with constant

speed.

Distance vs Time - Acceleration

0

100

200

300

400

500

600

0 1 2 3 4 5 6 7 8 9 10

Time (seconds)

Dis

tanc

e (m

eter

s)

Distance vs Time - Negative Acceleration

0

100

200

300

400

500

600

0 1 2 3 4 5 6 7 8 9

Time (min)

Dis

atnc

e (m

eter

s)Velocity vs Time - Acceleration

020406080100120140160180

0 1 2 3 4 5 6 7 8 9 10

Time (min)

Velo

city

(m/s

)

MOTION GRAPHS

Velocity vs Time - Negative Acceleration

0

100

200

300

400

500

600

0 1 2 3 4 5 6 7 8 9 10

Time (min)

Vel

ocity

(m/s

)

Velocity vs Time - Constant Speed

02

46

810

1214

16

0 1 2 3 4 5 6 7 8 9 10

Time (min)

Vel

ocity

(m/s

)

Distance vs Time - Constant Speed

010

2030

4050

6070

80

0 1 2 3 4 5

Time (min)

Dis

tanc

e (m

)

A train accelerated from 5 km/hr to 55 km/hr in 0.5 hr. What was the rate of acceleration?

100 km/hr/hr

http://www.youtube.com/watch?v=Uy3nATe85Kg&feature=relatedGravity and acceleration

http://www.youtube.com/watch?v=_BM89yVZoBg Eureka video- Measuring Acceleration

ACCELERATION TELLS HOW FAST IT IS MOVING SHOWS HOW FAST VELOCITY IS CHANGING HAS DIRECTION

SPEEDING UP

SLOWING DOWN

CHANGING DIRECTION