9.5 Space journey — travelling in space 1

Space journey —travelling in space

9.9.55

Hi!

9.5 Space journey — travelling in space 2

Let’s take a look at the journey in space.

9.5 Space journey — travelling in space 3

Spacecraft in frictionless motion

no air in space

no air resistance

✘

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Spacecraft in frictionless motion

in frictionless motion

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Spacecraft in frictionless motionSpace shuttle orbiting the Earth

does not need to fire its engine

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Living in a spacecraft

Let’s take a look at our life in space!

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WeightlessnessWhen a spacecraft is orbiting the Earth …

astronauts float around and do not

feel their weight

weightlessness (無重 )

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Weightlessness

force exerted on the ground by you

reaction exerted on you by the ground

That’s why you feel your weight.

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Weightlessness

Under what conditions can we feel weightless?

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Weightlessness

When the supporting reaction force disappears …

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WeightlessnessJust like when you are on a turbo drop …

Wow!

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Weightlessness

both you and your seat fall freely

separated from the seat; no reaction force to support you

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WeightlessnessWhen a spacecraft is orbiting the Earth …

astronauts float inside

no action force on the spacecraft

no reaction force from the spacecraft

astronauts feel weightless

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http://www.universetoday.com/95308/why-are-astronauts-weightless-in-space/

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A spacecraft travelling in space is in frictionless motion.

Spacecraft in frictionless motion

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Living in a spacecraft

Astronauts feel weightless in space.

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Daily life inside a spacecraft

Foods are individually packaged and precooked.

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Daily life inside a spacecraft

Water is recycled from astronauts’ urine as the supply of water is limited.

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Daily life inside a spacecraft

Astronauts stand by fixing their feet in foot restraints.

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Daily life inside a spacecraft

Astronauts exercise regularly to keep bones and muscles strong.

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Daily life inside a spacecraft

When sleeping, they fix themselves in ‘beds’ to avoid floating around.

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Daily life inside a spacecraft

Astronauts move like divers under weightless conditions.

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Daily life inside a spacecraft

What other problems do astronauts face in space?

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9.4Living in space

Match one solution to each of the problems.

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9.41 In space, there is no air for astronauts to breathe.

a The spacecraft are equipped with big solar panels to collect solar energy from the Sun and to change the solar energy to electrical energy.b The spacecraft must be airtight to prevent air from leaking into space. In addition, water is broken down by electricity to produce oxygen.c Astronauts communicate with each other using

radio signals.

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9.4

a The spacecraft are equipped with big solar panels to collect solar energy from the Sun and to change the solar energy to electrical energy.b The spacecraft must be airtight to prevent air from leaking into space. In addition, water is broken down by electricity to produce oxygen.c Astronauts communicate with each other using

radio signals.

2 The spacecraft may not be able to carry enough cells to power all its equipment for its whole

journey.

solar panels

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9.4

a The spacecraft are equipped with big solar panels to collect solar energy from the Sun and to change the solar energy to electrical energy.b The spacecraft must be airtight to prevent air from leaking into space. In addition, water is broken down by electricity to produce oxygen.c Astronauts communicate with each other using

radio signals.

3 Sound cannot travel in space because there is no air in space. Astronauts working outside the spacecraft cannot talk to each other directly.

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Due to the condition of weightlessness and the limited supply of resources, astronauts have difficulty in doing everyday activities such as eating, drinking and sleeping. Scientists have found ways to solve these problems.

Daily life inside a spacecraft

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Working outside a spacecraftWhat’s the difference between working on Earth and working in space?

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Working outside a spacecraftProblems faced when working outside the spacecraft in space:

no air to breathe

exposed to extreme temperatures and strong radiations

may be hit by tiny meteoroids

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Working outside a spacecraftAstronauts must wear spacesuits (太空衣 ) to protect themselves.

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Working outside a spacecraft

How do spacesuits work?

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Working outside a spacecraft

First, let’s learn about some ways heat is transferred.

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551a Astronauts feel weightless in space

because there is no air in space.

FT

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55b Astronauts in space exercise regularly to keep their bones and muscles strong.

FT

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55c There is no air in space.

FT

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552 State two features of a spacesuit and explain how they protect astronauts when they work outside a spacecraft.

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552 The visor is coated with a thin layer

of gold:

it reflects strong sunlight to protect the astronaut’s eyes.

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552 The outermost garment is shiny and

white in colour:

it reflects heat transferred by radiation to protect the astronaut from the strong direct sunlight.

(Accept other reasonable answers.)

Excellent!