4-9 Knowing more 4.3 (4.3)

The speed of light (knowing more 4.3)
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Slide 1: Tekstslide
NatuurkundeMiddelbare schoolhavo, vwoLeerjaar 2

In deze les zitten 13 slides, met interactieve quizzen en tekstslides.

Lesduur is: 45 min

Onderdelen in deze les

The speed of light (knowing more 4.3)

Slide 1 -Tekstslide

Lesson goals:
- Understand and explain how
fast light moves
- Understand and explain what
a light-year is
- Make calculations with
the concept of light-years

Slide 2 -Tekstslide

The speed of light
- In one second light travels a distance of 300 000 km
- With the vast distances in space, light needs time to travel
For example:
The distance from the sun
to the earth is 150 miljoen km,
and sunlight needs 8,3 minutes
to reach the earth.

Slide 3 -Tekstslide

Light of the stars
- The light of the closest star
takes 4 years before reaching the
earth.
- Light from most stars that we see
is light that has been traveling for several decades before they reached the earth.
- The best telescopes can see light that has been traveling for
13 billion lightyears.

Slide 4 -Tekstslide

Mars rover
The distance between Earth and
Mars varies between 56 million
and 400 million km.
At the greatest distance between these planets, it takes 22 minutes to send a signal to mars, and therefore to make contact with the mars rover.
(This is because radio waves also move with the speed of light)

Slide 5 -Tekstslide

Light-year
- Due to the vast distances in space,
meters and kilometers are inconvenient units to use.
For example, the closest star is
40 500 000 000 000 km from the earth
THEREFORE - we use light-years as a measure of distance in space. (It is the distance traveled by light in one year)
1 light-year = 9,5 trillion km

Slide 6 -Tekstslide

What is the speed of sound?
A
340 m/s
B
300 000 km/s

Slide 7 -Quizvraag

How long does it take for the light of the closest star to reach earth (don't consider the sun)?
A
7 seconds
B
8,3 minutes
C
4 years
D
150 years

Slide 8 -Quizvraag

Is a light-year a unit of time or a unit of distance?
A
time
B
distance

Slide 9 -Quizvraag

Why do we use the unit of light-years?

Slide 10 -Open vraag

Show with a calculator that a light-year is
9,5 trillion km (make a photo of your calculation)

Slide 11 -Open vraag

Now do the following activities
on p. 180
58 up to 60

No discussion
8 minutes

When you are done, research the question 'how large is the universe' ...
timer
8:00

Slide 12 -Tekstslide

Conclusion
• Speed of light = 300 000 km/s
• Distances in the universe are so vast that we use light-years as a unit of distance. One light-year = 9,5 trillion km
• The formula of velocity is useful when making calculations
ps
1 trillion = 1 000 billion = 1 000 000 million = 1 000 000 000 thousand