8.1 solar system

Question 1

What allows planets and satellites to
maintain circular orbits?

Answer 1

● Gravity provides the gravitational force
that acts as the object’s centripetal force
● The presence of a centripetal force
allows for the object to maintain its
circular orbit

Question 2

What type of satellite can a planet’s
moon be described as?

Answer 2

natural

Question 3

Give two examples of artificial satellites

Answer 3

1. TV satellites
2. Satellites used for satellite imaging

Question 4

Explain why for a stable orbit, the radius
of orbit must change if the speed
changes

Answer 4

● At higher speeds, the object requires a greater
centripetal force
● For a greater centripetal force, the
gravitational force must increase
● This is achieved by the radius of the orbit
being reduced

Question 5

Explain how the force of gravity acting on a satellite
affects its speed and velocity

Answer 5

● The force can alter its velocity since the
direction is continually changing
● It can’t cause a change of speed since
there is no force component in the direction
of motion