space

Question 1

which galaxy is our solar system apart of?

Answer 1

the milky way

Question 2

state the order of the planets

Answer 2

• mercury
• venus
• earth
• mars
• jupiter
• saturn
• uranus
• neptune

Question 3

what type of body do planets orbit around?

Answer 3

• our planets orbit around the sun
• the sun is a star

Question 4

what type of force pulled together the clouds of dust and gas to form the sun?

Answer 4

gravitational force of attraction

Question 5

what word is used to describe a cloud of dust and gas?

Answer 5

a nebula

Question 6

when do fusion reactions take place?

Answer 6

• at the start of a star’s life cycle
• when dust and gas are drawn together

Question 7

what determines the type of lifecycle a star undergoes?

Answer 7

the size of the star

Question 8

what two phases do all stars (the same size or greater than the sun) undergo?

Answer 8

• protostar phase
• mainsequence phase

Question 9

what do stars of a similar magnitude to the sun become at the end of their lifecycle?

Answer 9

a black dwarf

Question 10

what two phases do small stars go through between being a main sequence and a black dwarf?

Answer 10

• red giant
• white dwarf

Question 11

what two phases to larger stars go through between being a main sequence and a neutron star/ black hole?

Answer 11

• red super giant
• supernova

Question 12

what are produced during the fusion processes of a star?

Answer 12

all naturally occurring elements

Question 13

what condition is required for fusion reactions to occur in a star?

Answer 13

very high temperature

Question 14

how are elements heavier than iron produced?

Answer 14

in a supernova

Question 15

hydrogen nuclei fuse to form…

Answer 15

… heavier elements

Question 16

how are elements distributed throughout the universe?

Answer 16

through the explosion of a supernova (massive star)

Question 17

what allows planets and stars to maintain circular orbits?

Answer 17

• gravity provides the gravitational force that acts as the object’s centripetal force
• the presence of a centripetal force allows for the object to maintain its circular orbit

Question 18

a planet’s moon can be described as…

Answer 18

… a natural satellite

Question 19

give two examples of artificial satellites

Answer 19

• TV satellites
• satellites used for satellite imaging

Question 20

explain why, for a stable orbit, the radius of the orbit must change if the speed changes

Answer 20

• at higher speed, the object requires a greater centripetal force
• for greater centripetal force, the gravitational force must increase
• this is achieved by the radius of the object being reduced

Question 21

explain how the force of gravity acting on a satellite affects its speed and velocity

Answer 21

• the force can alter velocity as the direction is continuously changing
  -it can’t cause a change of speed since there is no force component in the direction of motion

Question 22

what is red-shift?

Answer 22

an observed increase in the wavelength of light from distant galaxies

Question 23

the further away the galaxy is…

Answer 23

… the faster it is moving, and the greater the observed increase of wavelength is

Question 24

red-shift provides evidence for?

Answer 24

• the universe expanding
• supports the big bang theory

Question 25

what does the big bang theory suggest?

Answer 25

- the entire universe started from a very hot, small, dense region in space

Question 26

is observed red-shift greater in a galaxy that’s closer or further away?

Answer 26

further

Question 27

what did scientists observe, providing evidence that the universe is expanding at a faster rate?

Answer 27

a supernovae- suggesting that galaxies are moving away at a faster rate

Question 28

prior to observations of the supernovae, what was believed about the expansion of the universe?

Answer 28

- the rate of expansion was expected to occur at a slower rate - as a result of gravitational forces slowing it down

Question 29

explain why a star is stable whilst it is in the main sequence stage of its life cycle

Answer 29

- gravitational forces (inwards) and forces as a result of fusion reactions (outward) - are in equilibrium

Question 30

describe what happens to a star between the main sequence stage, and the end of its life cycle

Answer 30

- star expands to become a red giant - star collapses to become a white dwarf - star cools to become a black dwarf

Question 31

explain why the velocity of a satellite changes as it orbits earth

Answer 31

- gravity causes the satellite to accelerate towards earth - acceleration causes a change in direction - velocity changes because direction changes

Question 32

which type of electromagnetic ray has the highest frequency?

Answer 32

gamma ray

Question 33

what makes microwaves suitable for sending communications to satellites?

Answer 33

can travel through the atmosphere

Question 34

what event leads to a neutron star forming?

Answer 34

explosion of a red super giant

Question 35

describe what will happen to the sun as it changes into a white dwarf?

Answer 35

- sun changes from main sequence into red giant - surface temperature decreases - relative luminosity increases - then, sun changes into a white dwarf - surface temperature increases - relative luminosity decreases