View by Category

Loading...

PPT – Speed, velocity and acceleration PowerPoint presentation | free to download - id: 76cf0-Njk0O

The Adobe Flash plugin is needed to view this content

About This Presentation

Write a Comment

User Comments (0)

Transcript and Presenter's Notes

Speed, velocity and acceleration

1 Both Mr Rabbit and Mr Tortoise took the same

round trip, but Mr Rabbit slept returned later.

Who runs faster?

No, I travelled longer distance every minute.

Me, as I spent less time on the trip.

Comment on their their argument.

2 A boy has been missing in a forest for 2 hours.

scale 1 cm 5 km

O

(a) If he walks at a speed of 4 km h1,

try to locate his possible positions on the map.

2 A boy has been missing in a forest for 2 hours.

scale 1 cm 5 km

O

(b) What else is important to spot the boy?

The direction in which he has been walking.

1 Speed

- How can we describe how fast an object moves?

E.g. A car on Tolo Highway travels 90 km in 1

hour.

We say that the car travels at a speed of 90 km

h1.

1 Speed

How can we describe how fast an object moves?

Speed is a measure of how fast something moves.

Speed distance travelled per unit of time

SI unit m s1

or km h1 (for long distances)

a Average speed

1 Speed

A car travels at 50 km h1,

slows down to 0 km h1,

and speeds up again to 60 km h1.

Its average speed over the whole journey

overall distance travelled

total time of travel

a Average speed

1 Speed

Average speed does not tell the variations during

the journey.

On most trips, the speed at any instant is often

different from the average speed.

b Instantaneous speed

1 Speed

Instantaneous speed

- speed at any instant

The word speed alone ? instantaneous speed

Instantaneous speed ? distance travelled in an

extremely short time interval

Simulation

b Instantaneous speed

1 Speed

Speedometer tells the cars speed at any instant!

2 Velocity

Velocity is...

a speed in a given direction or

rate of change of displacement.

a vector quantity

velocity

a Speed with direction

2 Velocity

MTR drivers concern speed only.

speed 90 km h1

Pilots concern velocity (direction speed).

speed 300 km h1 direction west

b Average velocity

2 Velocity

overall displacement

Average velocity

total time of travel

direction of overall displacement

direction of velocity

c Instantaneous velocity

2 Velocity

- The velocity at any instant is called

instantaneous velocity.

If a car moves at a constant velocity...

its average and instantaneous velocities have

the same value.

Q1 The world record...

The world record of women 100-m race is 10.49 s.

What is the average speed?

100

9.53 m s1 or 34.3 km h1

Q2 In an orienteering event...

In an orienteering event, Maria and Karen reach

their control points at the same time.

start, 1000 am

Maria, 1030 am

Karen, 1030 am

Who runs in a higher average velocity?

Q2 In an orienteering event...

Who runs in a higher average velocity?

A Maria. B Karen. C Undetermined since their

paths are unknown. D Incomparable since they run

along different directions.

Q3 True or false

Average speed of an object ? magnitude of its

average velocity.

(T/F)

Note The distance travelled is equal to

magnitude of displacement only if it is a

straight-line motion. Speed is usually larger

than the magnitude of velocity.

Q4 True or false

A man takes a walk starting from rest and ending

at rest.

It is possible for him to attain an average speed

of 5 km h1 but he never goes faster than 5 km

h1.

(T/F)

3 Acceleration

- When a car moves faster and faster,

its speed is increasing (velocity changed).

3 Acceleration

When a car moves slower and slower,

its speed is decreasing (velocity changed).

3 Acceleration

When a car changes direction,

its velocity changes too.

3 Acceleration

Acceleration measures the change in velocity

Acceleration ?velocity per unit time

overall change in velocity

total time taken

vector quantity

m s2

Unit m s1 / s

3 Acceleration

If a car accelerates at 2 m s2, what does that

mean?

v 0

t 0

v 2 m s1, ?v 2 m s1

t 1 s

1 m

v 4 m s1, ?v 2 m s1

t 2 s

3 m

t 3 s

v 6 m s1, ?v 2 m s1

5 m

Example 1

Airport Express takes 0.35 h to go from HK

station to Airport station (34 km).

? Ave. speed

34 km/0.35 h

97 km h1

Complete table.

Example 1

(b) Kln ? Tsing Yi

distance / ave. speed

Time

8.9 / 90

0.0989 h

356 s

Example 1

(a) Tsing Yi ? Airport

Distance

ave. speed ? time

105 ? 12.7

22.2 km

762 s (762/3600) h 12.7 h

Example 1

(c) HK ? Kln

distance / time

Ave. speed

2.6 / 0.0425

61.2 km

153 s (153/3600) h 0.0425 h

Example 2

A man walks from A to B at 1 km h1,

and returns at 2 km h1.

1 km h1

A

B

Average speed for the whole trip ?

Example 2

1 km h1

A

B

? whole journey 2 km

Suppose AB 1 km

Time for whole trip

1 h 0.5 h 1.5 h

Ave. speed distance / time

2/1.5

1.33 km h1

Example 3

A car travels 7 km north and then 3 km west in 10

minutes. Find

(a) average speed,

Ave. speed

3 km

B

C

distance travelled

time taken

7 km

60 km h1

A

Example 3

A car travels 7 km north and then 3 km west in 10

minutes. Find

(b) ave. velocity?

3 km

B

C

AC

7 km

7.62 km

tan q

? q 23.2o

3/7

A

Example 3

A car travels 7 km north and then 3 km west in 10

minutes. Find

(b) ave. velocity?

3 km

AC 7.62 km, q 23.2o

B

C

Size of ave. velocity

displacement

7.62 km

7 km

time

(10/60) h

45.7 km h1

Ave. velocity is 45.7 km h1, 23.2 north of west.

A

Example 4

The Ferrari 348 can go from rest to 100 km h1

in 5.6 s.

What is its ave. acceleration (in m s2)?

Ave. acceleration

4.96 m s2

Q1 A running student...

A running student is slowing down in front of a

teacher.

With reference to the sign convention,

Velocity of student positive / negative

Acceleration of student positive / negative

Q2 When time is measured...

Unit of time hour (h)

Unit of distance/displacement kilometer (km)

Quantity Unit

Scalar/Vector Speed ______

_____ Velocity ______

_____ Change in velocity ______

_____ Acceleration ______

_____

km h1

scalar

km h1

vector

km h1

vector

km h2

vector

Q3 In 2.5 s, a car speeds up...

In 2.5 s, a car speeds up from 60 km h1 to 65 km

h1...

while a bicycle goes from rest to 5 km h1.

Which one has the greater acceleration?

They have the same acceleration!

Q4 A car is moving in positive...

A car is moving in ve direction.

What happens if it moves under a ?ve

acceleration?

The car will slow down.

What happens if it moves under a ?ve

deceleration?

The car will move in ve direction with

increasing speed.

About PowerShow.com

PowerShow.com is a leading presentation/slideshow sharing website. Whether your application is business, how-to, education, medicine, school, church, sales, marketing, online training or just for fun, PowerShow.com is a great resource. And, best of all, most of its cool features are free and easy to use.

You can use PowerShow.com to find and download example online PowerPoint ppt presentations on just about any topic you can imagine so you can learn how to improve your own slides and presentations for free. Or use it to find and download high-quality how-to PowerPoint ppt presentations with illustrated or animated slides that will teach you how to do something new, also for free. Or use it to upload your own PowerPoint slides so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world. Or use it to create really cool photo slideshows - with 2D and 3D transitions, animation, and your choice of music - that you can share with your Facebook friends or Google+ circles. That's all free as well!

For a small fee you can get the industry's best online privacy or publicly promote your presentations and slide shows with top rankings. But aside from that it's free. We'll even convert your presentations and slide shows into the universal Flash format with all their original multimedia glory, including animation, 2D and 3D transition effects, embedded music or other audio, or even video embedded in slides. All for free. Most of the presentations and slideshows on PowerShow.com are free to view, many are even free to download. (You can choose whether to allow people to download your original PowerPoint presentations and photo slideshows for a fee or free or not at all.) Check out PowerShow.com today - for FREE. There is truly something for everyone!

You can use PowerShow.com to find and download example online PowerPoint ppt presentations on just about any topic you can imagine so you can learn how to improve your own slides and presentations for free. Or use it to find and download high-quality how-to PowerPoint ppt presentations with illustrated or animated slides that will teach you how to do something new, also for free. Or use it to upload your own PowerPoint slides so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world. Or use it to create really cool photo slideshows - with 2D and 3D transitions, animation, and your choice of music - that you can share with your Facebook friends or Google+ circles. That's all free as well!

For a small fee you can get the industry's best online privacy or publicly promote your presentations and slide shows with top rankings. But aside from that it's free. We'll even convert your presentations and slide shows into the universal Flash format with all their original multimedia glory, including animation, 2D and 3D transition effects, embedded music or other audio, or even video embedded in slides. All for free. Most of the presentations and slideshows on PowerShow.com are free to view, many are even free to download. (You can choose whether to allow people to download your original PowerPoint presentations and photo slideshows for a fee or free or not at all.) Check out PowerShow.com today - for FREE. There is truly something for everyone!

presentations for free. Or use it to find and download high-quality how-to PowerPoint ppt presentations with illustrated or animated slides that will teach you how to do something new, also for free. Or use it to upload your own PowerPoint slides so you can share them with your teachers, class, students, bosses, employees, customers, potential investors or the world. Or use it to create really cool photo slideshows - with 2D and 3D transitions, animation, and your choice of music - that you can share with your Facebook friends or Google+ circles. That's all free as well!

For a small fee you can get the industry's best online privacy or publicly promote your presentations and slide shows with top rankings. But aside from that it's free. We'll even convert your presentations and slide shows into the universal Flash format with all their original multimedia glory, including animation, 2D and 3D transition effects, embedded music or other audio, or even video embedded in slides. All for free. Most of the presentations and slideshows on PowerShow.com are free to view, many are even free to download. (You can choose whether to allow people to download your original PowerPoint presentations and photo slideshows for a fee or free or not at all.) Check out PowerShow.com today - for FREE. There is truly something for everyone!

For a small fee you can get the industry's best online privacy or publicly promote your presentations and slide shows with top rankings. But aside from that it's free. We'll even convert your presentations and slide shows into the universal Flash format with all their original multimedia glory, including animation, 2D and 3D transition effects, embedded music or other audio, or even video embedded in slides. All for free. Most of the presentations and slideshows on PowerShow.com are free to view, many are even free to download. (You can choose whether to allow people to download your original PowerPoint presentations and photo slideshows for a fee or free or not at all.) Check out PowerShow.com today - for FREE. There is truly something for everyone!

Recommended

«

/ »

Page of

«

/ »

Promoted Presentations

Related Presentations

Page of

CrystalGraphics Sales Tel: (800) 394-0700 x 1 or Send an email

Home About Us Terms and Conditions Privacy Policy Contact Us Send Us Feedback

Copyright 2017 CrystalGraphics, Inc. — All rights Reserved. PowerShow.com is a trademark of CrystalGraphics, Inc.

Copyright 2017 CrystalGraphics, Inc. — All rights Reserved. PowerShow.com is a trademark of CrystalGraphics, Inc.

The PowerPoint PPT presentation: "Speed, velocity and acceleration" is the property of its rightful owner.

Do you have PowerPoint slides to share? If so, share your PPT presentation slides online with PowerShow.com. It's FREE!

Committed to assisting Kyc University and other schools with their online training by sharing educational presentations for free