Speed

• Science
• Lower Secondary (Key Stage 3)

Unit 4 Physical world

Chapter 26 - Speed

What is the connection

Distance 

Time

Speed

cm

km

m

mm

s

h

m/s

km/s

cm/s

mm/s

What is the correct way to calculate speed

1. S=d + t
2. S=d - t
3. S=d / t
4. S=d x t

What is the correct way to calculate time

1. t = d + S
2. t = d/S
3. t = S - d
4. t = d - S

What is the correct way to calculate distance

1. d = s x t
2. d = t + s
3. d = s/t
4. d = t - s

What is velocity?

• Velocity is how fast an object or an person moves.
• it can present itself in km/h or m/s
• Acceleration is a type of velocity

What is

Acceleration?

But also

Deceleration

Speed

• A change in distance over time
  

Acceleration

• A change in speed over time 
  

Speed

• A change in distance over time
  
• Speed = Distance/time

Acceleration

• A change in speed over time 
  
• Acceleration = (End speed-start speed)/time taken for change in speed

Acceleration = (End speed-start speed)/time taken for change in speed

A car is moving at a speed of 4 ms-1. After 12s it is moving at a speed of 28ms-1. Calculate the acceleration of the car.

Answer

Acceleration = (End speed-start speed)/time taken for change in speed

=(28-4)/12

=24/12

= 2 ms -2

Make excercises + flashcards

Exercises:

Page 167 - 2 - 6, 10, 12

What you can't finish will be homework!