# Homework Help: Satellite - resistance (retarding force)

1. Mar 20, 2017

### charlie05

1. The problem statement, all variables and given/known data
What is the average resistance force F acting on the satellite during its flight, m = 3000kg, h=300km.

2. Relevant equations

3. The attempt at a solution
If it is llow orbit, so it inhibits the resistance of the atmosphere. In 300 km is no air, so no resistance ....?

2. Mar 20, 2017

### BvU

What equation are you using to calculate air pressure at 300 km ?

3. Mar 20, 2017

### charlie05

?

4. Mar 20, 2017

### charlie05

p0 = 101 325 Pa
h= 300 000m
g=9,81 m/s2
ρ 0 = 1,225 kg/m3

5. Mar 20, 2017

### charlie05

p 300 000 = 101 325*e-35,58 Pa

6. Mar 20, 2017

### BvU

7. Mar 20, 2017

### BvU

Agree it isn't much. What is the question (the full problem statement) ?

8. Mar 20, 2017

### charlie05

Yes I agree. Therefore, I think that is a resistive force is zero.

9. Mar 20, 2017

### BvU

According to your terse problem statement they ask for the average reisistance during its flight.
If its flight is circling the earth for 30 years it might be relevant to come up with a non-zero number.
But if its flight is a launch from sea level all the way up to 300 km I suppose you can ignore the pressure up there.

That's why I asked for the full problem statement

10. Mar 20, 2017

### charlie05

I understand. I have to ask my teacher. Yet I thank you for the effort and help.