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The emissivity of tungsten is 0.350. A tungsten sphere with a radius of 1.80 cm is suspended within a large evacuated enclosure whose walls are What power input is required to maintain the sphere at a temperature of 2900.0 K if heat conduction along the at a temperature of 300.0 K. supports is neglected? Take the Stefan-Boltzmann constant to be 5.67x10-8 W/(m' . K*). Express your answer in watts. DA AEd ? P = WA large research balloon containing 2.00 x 10*m of helium gas at 1.00 atm and a temperature of 15.0 * C rises rapidly from ground level to an altitude at which the atmospheric pressure is only 0.900 atm (the figure ( Figure 1)). Assume the helium behaves like an ideal gas and the balloon's ascent is too rapid to permit much heat Part A exchange with the surrounding air. Calculate the volume of the gas at the higher altitude. Figure