# Two quick orbit orbit qs!

#### bon

1. 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?

2. Homework Equations

3. 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

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#### tiny-tim

Homework Helper
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?

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