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Harris Academy N4 Physics > Space > Flashcards

Flashcards in Space Deck (33)
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1

What is the difference between mass and weight?

Mass is a measure of the partcles that make an object up. Weight is a force caused by the gravitational field strength of a planet.

2

What is meant by gravitational field strength?

Force per unit mass

3

An astronaut has a mass of 50kg. What will happen to the astronauts mass on the Moon?

It stays at 50kg. Mass does not change.

4

An astronaut has a mass of 50kg. What will happen to the astronauts weight on the Moon?

The weight will decrease as there is a lower gravitaional field strength on the Moon.

5

What are the possible dangers of space exploration?

  • Training accidents
  • Fire
  • Rocket malfunction
  • Vehicle Break-up
  • On board explosion
  • Depressurisation
  • Space suit failure
  • Control failures
  • Heat shield failure
  • Parachute failure

6

What are the two main challenges of re-entry?

  • Angle of re-entry
  • High temperatures / heating effect

7

Explain why the angle of re-entry poses a challenge.

The angle of re-entry to the atmosphere is important

  • too steep and the change in kinetic energy being transferred to heat is too fast resulting in overheating and possible rocket break-up
  • If the angle is too shallow you will skip off the atmosphere.

8

Explain why re-entering the atmosphere poses a challenge.

  • When a space craft is in space there is no friction as space is a vacuum.
  • When you re-enter the Earth’s atmosphere you go from no friction to lots of friction (caused by the atmosphere).
  • The result is that the space craft loses kinetic energy and slows down.
  • However due to conservation of energy, the energy is not lost but is converted to heat.
  • The outside of the space craft becomes incredibly hot.
  • This means that the space vehicle requires thermal shielding.

9

List some benefits of space exploration.

  • Satellite communications
  • GPS and SatNav technologies
  • Weather forecasting / storm tracking
  • Improved mapping
  • Spin off technologies - hand held drills, portable DVD players, memory foam

10

Name one man made object that has helped us explore space.

  1. Hubble Space Telescope
  2. Voyager Probes
  3. Cassini - Huygens

11

What is the 'observable universe'?

The observable universe is the furthest point that we can ‘see’ or detect. The furthest point that we can ‘see’ is the distance which light must have travelled for the whole age of the universe.

12

What is meant by a star?

A ball of burning gas

13

What is meant by a planet?

An object that orbits a star

14

What is meant by a moon?

An object that orbits a planet

15

What is a star and it's orbitting planets called?

Solar system

16

What is an exoplanet?

A planet ouwith our solar system

17

What is a galaxy?

Vast collections of stars, gas, dust held together by gravity

18

What is a ball of burning gas?

Star

19

What is an object that orbits a star?

Planet

20

What is an object that orbits a planet?

moon

21

What is a star and it's orbitting planets called?

Solar system

22

What do you call a planet outside our solar system?

Exoplanet

23

What is  a vast collections of stars, gas, dust held together by gravity called?

Galaxy

24

What is a light year?

The distance that light can travel in one year

25

Why do we use light years?

Distances in space are so huge we need a big unit to measure it in.

26

What does an exoplanet need to sustain life?

Liquid water

27

What is a geostationary satellite?

A satellite that remains above the same point on the Earth

A satellite that has a period of 24 jours

28

State three uses for satellites

  • Telecommunications
  • Monitoring weather
  • Mapping
  • GPS
  • Monitoring environmental change (desert size, ice sheets)

29

What effect does height above the Earth have on a satellite?

The higher the satellite the longer it takes to orbit the Earth

30

Why is a curved reflector used to receive signals?

  • Collects a large amount of signal
  • Focuses it to a point

31

Why is a curved reflector used to transmit signals?

It gives a parallel beam of signal that can be directed.

32

What would a diagram look like to show the effect of a curved reflector being used as a transmitter?

See diagram

33

What would a diagram look like to show the effect of a curved reflector being used as a receiver?

See diagram