Topic 8 Astrophysics

Question 1

What is the universe?

Answer 1

A large collection of billions of galaxies

Question 2

What is a galaxy?

Answer 2

A large collection of billions of stars

Question 3

Where is our solar system?

Answer 3

In the Milky Way

Question 4

How does gravitational field strength vary?

Answer 4

The larger the mass of the planet, the greater the gravitational field strength.The larger the distance the planet if from the sun, the greater the gfs is.

Question 5

What does gravitational force cause?

Answer 5

• moons to orbit planets
• planets to orbit the sun
• artificial sattelites to orbit the earth
• comets to orbit the sun

Question 6

What is the orbit of a comet like?

Answer 6

Comets are a ball of dust and frozen gas with wide elliptical orbits.

Question 7

What is the orbit of a planet like?

Answer 7

Planets orbit stars in a circular shape

Question 8

What is the orbit of a moon like?

Answer 8

Moons orbit planets in a circular shape

Question 9

What equation shows the relationship between speed, orbital radius and time?

Answer 9

orbital speed=2x πxr / time period

Question 10

Find out the orbital speed of Mars which has a radius from the Sun of 2.34x10^8km and a year of 1.9 years.

Answer 10

orbital speed=2xπx2.34x10^8 / 1.9

=772823874.7km/year