Chapter 6 - Astronomy Flashcards
Difference between a planet and an asteroid?
Planets are bigger
Difference between an asteroid and a comet?
- Comet has an icy surface
- Asteroids are rocky
What shape is the Milky Way?
- Spiral
What is the formula for orbital speed?
time period
Telescope completes one orbit in 96 minutes.
The radius is 6960km
Calculate its orbital speed in m/s
(6960 times by 1000 = 696,000,0)
2 x π x 696,000,0
—————–
96 x 60
= 7592 m/s
The Chandra Telescope also orbits the Earth, but does not move in a circular orbit.
Its distance from the Earth and its speed change as it orbits the Earth.
It travels fastest when it is closest to the Earth.
Use ideas about energy to explain why [3 marks]
- GPE reduces when closer;
- Therefore KE increases;
- because total energy conserved
Explain why a comet travels fastest near the sun [1 mark]
- Closer to Sun
- Gravitational force strongest
The gravitational field strength is smaller on the Moon than on the Earth.
Suggest why [1 mark]
Moon has less mass than Earth
Example of an artificial satellite and a natural satellite [2 marks]
Natural - Moon
Artificial - Sat Nav Systems
what is the universe [1 mark]
- a large collection of billions of galaxies
What is a galaxy [1 mark]
- A large collection of billions of stars
Where is the solar system [1 mark]
- Solar system is in the Milky Way galaxy
What causes moons to orbit planets [1 mark]
- gravitational force
What causes planets to orbit the sun [1 mark]
Gravitational force
What causes artificial satellites to orbit the Earth [1 mark]
- gravitational force
