space

Question 1

What is a light year?

Answer 1

The distance light can travel in one earth year

Question 2

What is the moon?

Answer 2

A non luminous object that orbits the planet

Question 3

What is a galaxy?

Answer 3

A large collection of dust, gas and stars held together by gravity

Question 4

What is a planet?

Answer 4

A non luminous spherical object that orbits a star. It must dominate its orbit.

Question 5

Name a non contact force

Answer 5

Gravitational attraction

Question 6

What is the equation linking speed, distance and time?

Answer 6

Speed= distance/time

Question 7

What is the equation for velocity?

Answer 7

Velocity= displacement/ time

Question 8

What is the difference between scalar and vector?

Answer 8

Scalar can only change in its magnitude whereas vector can change in it magnitude AND direction

Question 9

What are the two forces that keep a star in stable equilibrium?

Answer 9

Radiation pressure and gravity

Question 10

What is an orbit?

Answer 10

A curved path a body takes around a larger body due to gravitational attraction

Question 11

Describe is the relationship between the distance from the sun and the orbital speed for a planet

Answer 11

The increase in the distance from the sun= decrease in the orbital speed of a planet

Question 12

What are the 6 stages of the life cycle of a star in order?

Answer 12

Nebula, protostar, main sequence, red giant, white dwarf, black dwarf

Question 13

What are the six stages of the life cycle of a REALLY BIG star?

Answer 13

Nebula, protostar, main sequence, red SUPER giant, supernova and then either neutron star or black hole.

Question 14

What is the difference between a neutron star and a black hole?

Answer 14

Neutron star is made from a high mass star and a black hole is made from a VERY high mass star

Question 15

Name the 8 planets in order

Answer 15

Mercury, Venus, earth, mars, Jupiter, Saturn, Uranus and Neptune

Question 16

What are the elements in a main sequence star?

Answer 16

Helium+ hydrogen

Question 17

Describe how stars like the sun are formed:

Answer 17

They are formed by gas in the nebula pulled together by gravity

Question 18

In which process do stars emit radiation (like light and heat)?

Answer 18

Fusion

Question 19

What are the conditions for a star to reach equilibrium?

Answer 19

The inward gravitational force must be balanced by the outward pressure generated by nuclear fusion

Question 20

What are two other conditions for a star to reach equilibrium?

Answer 20

Energy generation+ temp and pressure gradient

Question 21

Explain how nuclear fusion releases energy

Answer 21

Lighter nuclei fuses to make a heavier nuclei

Question 22

What does a star orbit?

Answer 22

The centre of its home galaxy

Question 23

What does a planet orbit?

Answer 23

Around a star

Question 24

What does the moon orbit?

Answer 24

Orbits around the earth

Question 25

How does a star remain stable for billions of years?

Answer 25

Radiation pressure and gravity are balanced

Question 26

How does the stable period end?

Answer 26

Hydrogen expires and star cools and swells

Question 27

What is the relationship of the masses of the dust and gas in a protostar with gravity?

Answer 27

Greater mass= bigger force

Question 28

What is the relationship between the distance of the dust and gas between gravity in protostar?

Answer 28

Greater distance= weaker gravitational force

Question 29

What is the most abundant element in universe?

Answer 29

Hydrogen

Question 30

What is made in the core of a main sequence star?

Answer 30

Helium

Question 31

What is the largest nucleus able to be made inside the core of a red giant?

Answer 31

Iron

Question 32

Approx how many natural occurring elements are there? (To the 10)

Answer 32

90

Question 33

What are the two possibilities for the end of life of a star bigger than our sun?

Answer 33

Neutron star or black hole

Question 34

Why is supernova a likely reason elements are distributed throughout space?

Answer 34

Supernova explosions spread matter across space

Question 35

Why would the sun not become a black hole?

Answer 35

Becomes a black wall as not enough mass for black hole

Question 36

Where does the helium in the sun originate?

Answer 36

The fusion of hydrogen

Question 37

Where does the helium on earth originate?

Answer 37

fusion of helium from previous stars, earth is made of matter of dead stars