Astrophysics

Question 1

What is the universe composed of?

Answer 1

A large collection of billions of galaxies

Question 2

Define a galaxy.

Answer 2

A large collection of billions of stars

Question 3

What is a solar system?

Answer 3

A collection of planets orbiting a common star

Question 4

Where is our solar system located?

Answer 4

In the Milky Way galaxy

Question 5

What is gravitational field strength measured in?

Answer 5

Newtons per kilogram (N/kg)

Question 6

What is the formula for weight?

Answer 6

weight = mass × gravitational field strength

Question 7

What does gravitational force enable?

Answer 7

Various bodies to orbit around others

Question 8

True or False: Moons orbit planets.

Answer 8

True

Question 9

What shape are the orbits of planets and comets?

Answer 9

Slightly elliptical for planets; highly elliptical for comets

Question 10

What is the relationship between orbital radius and speed?

Answer 10

The greater the orbital radius, the greater the orbital speed

Question 11

What happens to a comet’s speed as it gets closer to the star?

Answer 11

It has a greater speed nearer to the star

Question 12

What initiates the formation of a star?

Answer 12

A cloud of dust & gas called a nebula

Question 13

What happens to particles in a nebula due to gravity?

Answer 13

They experience a weak attraction and begin to clump together

Question 14

What is a protostar?

Answer 14

The stage after particles in a nebula clump together

Question 15

What occurs when pressure and temperature in a star are great enough?

Answer 15

Nuclear fusion occurs

Question 16

What do hydrogen nuclei fuse to form?

Answer 16

Helium nuclei

Question 17

What is a main sequence star?

Answer 17

A stable star where outward pressure balances with gravitational pressure

Question 18

What happens when a star uses up its hydrogen?

Answer 18

It collapses under its own gravitational attraction

Question 19

What does a star with a similar mass to the Sun become after collapsing?

Answer 19

A red giant

Question 20

What is the final stage of a star after becoming a white dwarf?

Answer 20

It cools into a black dwarf

Question 21

What is the sequence of stellar evolution for a massive star?

Answer 21

Nebula → Protostar → Main Sequence Star → Red Supergiant → Supernova → Neutron Star or Black Hole

Question 22

Fill in the blank: A _______ is the stage after a nebula where particles begin to clump together.

Answer 22

Protostar

Question 23

What happens to a star with a mass larger than the Sun?

Answer 23

It expands and becomes a red super giant before exploding in a supernova.

The remnants can be either a neutron star or a black hole if exceptionally massive.

Question 24

What classification method is used for stars?

Answer 24

Stars can be classified according to their colour.

The colour is related to the surface temperature of the star.

Question 25

What is the relationship between a star’s colour and its surface temperature?

Answer 25

Hotter stars are bluer and cooler stars are redder.

Question 26

Fill in the blank: A star with a mass larger than the Sun becomes a _______ before it explodes.

Answer 26

red super giant

Question 27

True or False: A black hole is a possible remnant of a supernova if the star was exceptionally massive.

Answer 27

True