Satelite orbiting earth in a circular path

[cortozld]

Homework Statement

What is the orbiting speed (m/s) of a satelite orbiting Earth in a circular path 1000 km above Earth's surface? (Use 4 sig figs)

Homework Equations

universal constant of 6.67E-11
r of Earth 6.37E6 m (given by teacher)
mass of Earth 6E24 kg (given by teacher)

derived v=sqrt(G*M/r)

this is what i have read will solve this equation for me

The Attempt at a Solution

First I converted the 1000 km above Earth to m and added that and the radiace of Earth together to get 7.67E6 m (r) then I solved for v: sqrt(6.67E-11*6E24/7.37E6)=7369 m/s

what am I doing wrong? There is also a possiblity that the teacher is wrong, its happened before on his website

 

[tiny-tim]

Welcome to PF!

Hi cortozld! Welcome to PF!

(have a square-root: √ )

r of Earth 6.37E6 m (given by teacher)
…
First I converted the 1000 km above Earth to m and added that and the radiace of Earth together to get 7.67E6 m (r) then I solved for v: sqrt(6.67E-11*6E24/7.67E6)=7369 m/s

You've used 7.67E6 instead of 7.37E6 …

does that make a difference? ​

 

[cortozld]

that was an accidental typo, my bad. I believe its my teachers website, he's been having lots of problems with it since the year started. So unless anyone has an idea about what I'm doing wrong I'll just have to talk to him on Mon.