P6 (*2)

?
  • Created by: Fiona2002
  • Created on: 14-01-18 10:20
What do planets orbit?
Stars
1 of 10
What do moons orbit?
Planets
2 of 10
How does gravity cause orbits?
A planet that moves near to a star will feel a gravitational force towards it, this force will cause the planet to travel towards whatever its orbiting, but as the planet is already moving it causes a change in direction- velocity change= circular
3 of 10
What is a stable orbit?
Stable orbit: object is orbiting at constant speed. The greater its speed or the smaller the orbital radius = the greater the force needed to keep it in stable orbit.
4 of 10
Stable orbit- speed?
A planet moving at a high speed will need to be closer to a star (more gravity) in order to be in stable orbit.
5 of 10
If the speed of an orbiting object changes, the orbital radius also changes - True or False
True
6 of 10
Describe what happens if an artificial satellite in a stable orbit slows down.
The satellite will be pulled into an orbit with a smaller orbital radius -this causes the speed of the object to increase.
7 of 10
How did the sun form?
Dust & gas were attracted by gravity & collapsed, they became denser and were compressed increasing the temp and pressure = Sun
8 of 10
What is the red shift?
Light from most distant galaxies have longer wavelengths and are shifted towards the red end of the spectrum. =light is moving away from us (receeding)
9 of 10
Describe the Big Bang theory.
First all the matter in the universe occupied a very small space, it was dense and hot, then it exploded which caused expansion! Improved telescopes have provided evidence for this.
10 of 10

Other cards in this set

Card 2

Front

What do moons orbit?

Back

Planets

Card 3

Front

How does gravity cause orbits?

Back

Preview of the front of card 3

Card 4

Front

What is a stable orbit?

Back

Preview of the front of card 4

Card 5

Front

Stable orbit- speed?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Earth in space resources »