SS: Galaxies

Forces and Motion
Lesson 14. 
Galaxies
1 / 33
next
Slide 1: Slide
PhysicsSecondary EducationAge 13

This lesson contains 33 slides, with interactive quizzes, text slides and 2 videos.

Items in this lesson

Forces and Motion
Lesson 14. 
Galaxies

Slide 1 - Slide

How are you today?
😒🙁😐🙂😃

Slide 2 - Poll

Highlights of the Day
  •  describe a galaxy in terms of stellar dust and gas, stars and planetary systems
  • Values :  Responsibility and Determination

Slide 3 - Slide

Arrange me!

Slide 4 - Slide

The 
Universe
star
solar system
planet
galaxy
moon

Slide 5 - Drag question

Slide 6 - Slide

Slide 7 - Slide

Slide 8 - Slide

Slide 9 - Slide

The Milky Way Galaxy
The word "galaxy" comes from the Greek word "galaxias" (γαλαξίας).

Slide 10 - Slide

What does "galaxias" mean?
A
milk
B
milky
C
stars

Slide 11 - Quiz

How many major shapes of galaxies do we know that exist?
A
1
B
2
C
3
D
4

Slide 12 - Quiz

Shapes of Galaxies

Slide 13 - Slide

Shapes of Galaxies

Slide 14 - Slide

What shape of galaxy does the Milky Way Galaxy exhibit?
A
elliptical
B
spiral
C
peculiar
D
lenticular

Slide 15 - Quiz

Slide 16 - Slide

Because we live in a spiral galaxy, we can only see one ‘arm’ of the spiral, which is that band across the sky. In fact, most of the stars we see at night are in our own galaxy. There are an estimated 250 000 000 stars in the Milky Way including our Sun.

Slide 17 - Slide

Because we live in a spiral galaxy, we can only see one ‘arm’ of the spiral, which is that band across the sky. In fact, most of the stars we see at night are in our own galaxy. There are an estimated 250 000 000 stars in the Milky Way including our Sun.

Slide 18 - Slide

TRUE or FALSE:
There are other galaxies in the universe besides our own.
A
TRUE
B
FALSE

Slide 19 - Quiz

TRUE or FALSE:
The word ‘planet’ is used to describe all of space and everything in it.
A
TRUE
B
FALSE

Slide 20 - Quiz

Slide 21 - Slide

The closest known galaxy to the Milky Way is called the _________ Galaxy. It is elliptical in shape and a distance of away from us.
A
Canis Major Dwarf
B
Andromeda
C
Triangulum

Slide 22 - Quiz

What are galaxies made of?

Slide 23 - Slide

Galaxies are made from stellar _________ , gas, stars and solar systems held together by gravity.
A
dust
B
fog
C
elements

Slide 24 - Quiz

Stellar dust is the dust that is found in space. The Earth is travelling through a cloud of stellar dust that is estimated to contain an average of one dust particle in every million cubic metres of space!

Slide 25 - Slide

The gravity holding a galaxy together is very strong because galaxies are very large and have very large mass. Even if you could travel at the speed of light (300 000 kilometres per second), it would take you more than 100 000 years to cross from one side of the Milky Way to the other! Scientists estimate the mass of the Milky Way to be 1 500 000 000 000 times the mass of the Sun.

Slide 26 - Slide

TRUE or FALSE
The gravity holding a galaxy is stronger than the gravity holding the planets in our solar system together.
A
TRUE
B
FALSE

Slide 27 - Quiz

How long will it take you to cross from one side of the Milky Way to the other?
A
100 000 years
B
1 000 000 years
C
10 000 years

Slide 28 - Quiz

Approximately, how heavy is the Milky Way Galaxy?
A
500 000 000 000 times the mass of the Sun
B
1 500 000 000 000 times the mass of the Sun
C
15 500 000 000 000 times the mass of the Sun

Slide 29 - Quiz

How many galaxies are there?
Scientists have counted the galaxies in one part of space. The scientists then multiplied this number up to estimate the number of galaxies in the universe. The answer they got was 
100 000 000 000 galaxies!

Slide 30 - Slide

Slide 31 - Video

Self-survey: Rate your level of understanding and participation in this lesson.
15

Slide 32 - Poll

Slide 33 - Video