# Lesson 5

TTO 2 – Science
Chapter 4. Speed
1 / 18
Slide 1: Tekstslide
ScienceMiddelbare schoolhavo, vwoLeerjaar 2

In deze les zitten 18 slides, met tekstslides.

Lesduur is: 45 min

## Onderdelen in deze les

TTO 2 – Science
Chapter 4. Speed

#### Slide 1 -Tekstslide

Exercise
You are an engineer at a formula one race track. One practice track has three parts to it. Part one with a length of 22,3 km. Part two with a length of 33,5 km. and part three with a length of 17,9 km. A race car speeds through this track two times. The first time it complets it in 19 minutes and 40.8 seconds the second time in 18 minutes and 27 seconds.

Calculate the average speed of this formula one race car in m/s.
avaragespeed=totaltimetotaldistance

#### Slide 2 -Tekstslide

Exercise
• A car travels 72km/h. What is that in m/s?
• A cyclist travels 7 m/s. What is that in km/h?

#### Slide 3 -Tekstslide

Exercise
• A car travels 72km/h. What is that in m/s?

• In one hour the car travels 72km = 72000 m
• One hour = 3600 seconds
• So in 3600 seconds it travels 72000 m
• Then in 1 second it travels 72000/3600 = 20 m/s
• So a speed of 72km/h converts to 20 m/s

#### Slide 4 -Tekstslide

Exercise
• A cyclist travels 7 m/s. What is that in km/h?

The cyclist travels 7 meters in one second
There are 3600 seconds in one hour
So in one hour the cyclist travels 7m x 3600 = 25200m
25200m = 25.2 km. the cyclist travels 25.2 km in on hour.
So a speed of 7 m/s converts to 25km/h.

#### Slide 5 -Tekstslide

This lesson
• Practice exercises
• Precision and accuracy
• Significant figures

#### Slide 6 -Tekstslide

Learning goals
• calculate average speed
• Converte km/h <-> m/s
• Explain the difference between Precision and accurarcy
•  Explain what is meant by significant figures

#### Slide 7 -Tekstslide

Precision and accuracy

#### Slide 8 -Tekstslide

Precision:
How detailed your measurement is
Accuracy:
How correct your measurement is

#### Slide 10 -Tekstslide

Significant figures
Three measurements for a 400 meter sprint.
43 seconds
00043 seconds
43,03 seconds

#### Slide 11 -Tekstslide

Significant figures
The amount of meaning numbers in a measurement.

Usain bolt

Time:
Yohan Blake

Time:
Justin Gatlin

Time:

#### Slide 13 -Tekstslide

Usain bolt

Time: 10 s
Yohan Blake

Time: 10 s
Justin Gatlin

Time: 10 s
Their 2012 times
1 significant number

#### Slide 14 -Tekstslide

Usain bolt

Time: 9.6 s
Yohan Blake

Time: 9.8 s
Justin Gatlin

Time: 9.8 s
Their 2012 times
2 significant number

#### Slide 15 -Tekstslide

Usain bolt

Time: 9.63 s
Yohan Blake

Time: 9.75 s
Justin Gatlin

Time: 9.79 s
Their 2012 times
3 significant number

Homework