Posted by Bobbie on .
What is the gravitational field strength at a place 220km above Earth's surface, the altitude of many piloted space flights?

Physics 
bobpursley,
Newtons law of gravity:
g=GMe/(radiusEarth + altitude)^2 
Physics 
Bobbie,
k well i don't know what Me stands for or what the altitude is or how to find it.

Physics 
bobpursley,
You should know Newtons Law.
Me is mass of the Earth.
altitude is 220Km, given. 
Physics 
Bobbie,
well my teacher cant teach so i dont. and i used the formula but i got a different answer then the back of the book. i don't get what im doing wrong.
g=GMe/(radius Earth+altitude)^2
g=(6.67x10*11Nm^2/kg^2)x(5.98x10*24kg)/ (6.38X10*6m+0.22m)^2
g= (3.99x10*14Nm^2/kg)/(4.07x10*13m^2)
g=9.8N/kg
the back of the book says 9.1N/kg 
Physics 
Bobbie,
well my teacher cant teach so i dont. and i used the formula but i got a different answer then the back of the book. i don't get what im doing wrong.
g=GMe/(radius Earth+altitude)^2
g=(6.67x10*11Nm^2/kg^2)x(5.98x10*24kg)/ (6.38X10*6m+0.22m)^2
g= (3.99x10*14Nm^2/kg)/(4.07x10*13m^2)
g=9.8N/kg
the back of the book says 9.1N/kg