P6- space

Question 1

What does the solar system contain

Answer 1

a) one star- the sun (closest star to the Earth)

b) Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune

c) Minor planets that orbit the Sun including dwarf planets (Pluto), asteroids in the asteroid belt

d) moons that orbit the planets

Question 2

Why do the planets orbit the Sun

Answer 2

Because the Sun contains most of the mass of the Solar System and the Gravitational attraction of the Sun.

Question 3

Describe the Sun

Answer 3

It is a star of medium size, consisting mostly of hydrogen and helium

It radiates most its energy in infrared, visible and ultraviolet regions of the electromagnetic spectrum.

Question 4

how are stable stars formed?

Answer 4

as protostars from interstellar clouds of gas and dust due to gravitational attraction

the next stages of the life cycle of a star depend on its mass

Question 5

What are the next stages of the life cycle of a small mass star

Answer 5

a small mass star (arnd same mass as sun): red giant-> white dwarf +planetary nebula

Question 6

What are the next stages of the life cycle of a large mass star

Answer 6

red supergiant-> supernova-> neutron star

Question 7

What are the next stages of the life cycle of a large mass star

Answer 7

red supergiant -> supernova-> black hole

Question 8

how are astronomical distances measured?

Answer 8

in light years- one light year is the distance travelled in space by light in one year

Question 9

time it takes for light to travel calculation

Answer 9

Distance / Speed of Light (3x10^8)

Question 10

orbital speed equations

Answer 10

v= 2πr/T
r is the radius of the orbit
T orbital period

Question 11

Relationship between strength of the distance from the sun vs Sun’s gravitational field & planet’s orbital speed

Answer 11

As the distance of the sun increases, strength of gravitational field decreases and orbital speed of the planets decrease

Question 12

What are stars powered by?

Answer 12

nuclear reactions that release energy

In stable stars the nuclear reactions involve the fusion of hydrogen into helium

Question 13

How else can a star be formed amidst a nebula from a supernova

Answer 13

a nebula emerging from a supernova may form new stars with orbiting planets

Question 14

What are galaxies made up of

Answer 14

Many billions of stars

e.g sun in the milky way (one of billions of galaxies

Question 15

what is the diameter of the Milky Way

Answer 15

approximately 100,000 light years

Question 16

what is the big bang theory supported by

Answer 16

• the universe expanded from a single point of high density and temperature

-the universe isstill expanding

-the universe is approx 13.8 Billion years old