What happens to the height of the orbit?

[bon]

Homework Statement

1) A satellite is in circular orbit around the sun. Which requires the greater change in satellite's speed: to escape the solar system or fall into the sun?

2)Why does atmospheric friction increase the speed of a satellite in low Earth orbit?

Homework Equations

The Attempt at a Solution

1) Not sure..Surely the change in speed in 2 cases would be the same?

2) Again ..not sure.. :S

 

[tiny-tim]

hi bon!

1) A satellite is in circular orbit around the sun. Which requires the greater change in satellite's speed: to escape the solar system or fall into the sun?

1) Not sure..Surely the change in speed in 2 cases would be the same?

(if the Sun has mass M and if the orbit has radius r …)

What initial speed is needed to escape to infinity?

What initial speed is needed to reach the Sun?

2)Why does atmospheric friction increase the speed of a satellite in low Earth orbit?

It stays in orbit: but what happens to the orbit?