Space

Question 1

what are 2 things artificial satellite used for?

Answer 1

• communicate
• orbiting telescope

Question 2

what is it called when the planets do not orbit the sun in a perfect circle

Answer 2

elliptical orbit

Question 3

asteroids

Answer 3

• made mainly of rock and metal
• asteroid belt found between mars and
  Jupiter

Question 4

comets

Answer 4

• made of ice and dust
• more elliptical orbits

Question 5

galaxy

Answer 5

collections of billions of stars

Question 6

1. main sequence star

Answer 6

1. nebula ( cloud of dust and gas)
2. overtime the attractive force of
   gravity pulled the dust and gas
   together to form a structure called a
   protostar
3. force of gravity gets stronger and
   denser meaning the temp rises
4. the particles collides
5. when temp is high, hydrogen nuclei
   undergo nuclear fission to form
   helium nuclei giving out huge amount
   of energy making the star core hot.

Question 7

2. main sequence star

Answer 7

1. outward pressure from nuclear
   fusion is balanced by the inward
   pressure from gravity causing a long
   stable period for billions of years
2. start to run out of hydrogen (fuel) so
   the inward pressure takes over and
   contracts the star into a small ball
3. star will become so hot and dense
   that nuclear fusion can take place
   again meaning the star will expand
4. forms heavier elements

Question 8

3. red giant

Answer 8

1. after time, it becomes unstable and
   expels its outer layers
2. leaves behind a white dwarf (hot,
   dense solid core) no nuclear fusion
3. white dwarf then gets cooler and
   darker until it emits all its energy
4. no longer has enough energy to emit
   light so becomes black dwarf

Question 9

3. red super giant

Answer 9

1. undergoes more nuclear fusion
2. after several cycles of expansion and
   contraction they eventually explode
   causing a supernova
3. supernova forms even more heavier
   elements that are ejected into the
   universe

Question 10

4. supernova

Answer 10

• Very big = neutron star
  -MASSIVE = black hole

Question 11

orbits

Answer 11

the curved path of one celestial object or spacecraft around another celestial object

Question 12

Newtons first law

Answer 12

and object traveling at a certain velocity will continue to travel at that velocity unless acted upon by a resultant force

Question 13

instantaneous velocity

Answer 13

the velocity right angle to the acceleration which keeps it travelling in a circle

Question 14

stable orbit

Answer 14

• instantaneous velocity
• strong gravitational pull

Question 15

size of orbit

Answer 15

smaller the object’s orbit the faster it has to be to maintain the stable orbit as the gravitational force will be greater

Question 16

red shift

Answer 16

the wavelengths are all longer than they should be as they’re shifted towards the red end of the spectrum

Question 17

Why is red shift happening?

Answer 17

the distant galaxies emitting the lights are moving away from us and are being stretched as they travel toward us

Question 18

what are the limitations of the balloon model

Answer 18

• balloons burst where the real universe
  isn’t likely to burst
• should be galaxies inside the balloon

Question 19

big bang theory

Answer 19

• initially all the matter in the universe
  occupied a very small space (dense
  and hot)
• it then exploded
• space itself started to expand
• the expansion is still continued until
  this day

Question 20

redshift equation

Answer 20

amount of wave length been shifted (difference between observed and original wavelength)
/ original wavelength

=

recessional velocity of galaxy
/ speed of light in vacuum ( 300,000,000 m/s)