Given that,
Energy 
Surface temperature = 11000 K
Emissivity e =1
(a). We need to calculate the radius of the star
Using formula of energy
Put the value into the formula
(b). Given that,
Radiates energy 
Temperature T = 10000 K
We need to calculate the radius of the star
Using formula of radius
Put the value into the formula
Hence, (a). The radius of the star is 
(b). The radius of the star is 
(if it's frictionless the length doesn't even matter :) )
It would have the same kinetic energy down as the potential energy up. That is,
or
(the mass doesn't even matter). The result is
, so only the height matters really. It is almost 9 (it is
).
Explanation:
Everything in Earth's system can be placed into one of four major subsystems: land, water, living things, or air. These four subsystems are called "spheres." Specifically, they are the "lithosphere" (land), "hydrosphere" (water), "biosphere" (living things), and "atmosphere" (air).
From the point of view of an observer located on the Earth - no.
Australia has the OPTUS satellites on the geostationary orbits.
