The emissivity of tungsten is 0.350. A tungsten sphere of radius 1.50 cm is suspended inside a large evacuated cavity wh

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The emissivity of tungsten is 0.350. A tungsten sphere of radius
1.50 cm is
suspended inside a large evacuated cavity whose walls are at 290
K.
A. What power input is required to keep the sphere at 3000 K if you
neglect
heat conduction by the supports?
B. If the power supplied to the sphere is less than the value
calculated at point
above that will occur with the equilibrium temperature of the
sphere
C. Comment qualitatively, with respect to heat transfer, what would
happen if
the supports that suspend the sphere are not negligible and the
cavity where it is
the sphere is not in a vacuum but contains air.