Answer to Question #58126 in Mechanics | Relativity for Christbeauty

Question

11 Calculate the electric power which must be supplied to the filament of of a light bulb operating at 3000K. The total surface area of the filament is
8×10−6m2
and its emissivity is 0.92.
20.3W
33.8W
46.4W
56.7W

12 Calculate the change in internal energy of 2kg of water at
90oC
when it is changed to
3.30m3
of steam at
100oC
. The whole process occurs at atmospheric pressure. The latent heat of vaporization of water is
2.26×106J/kg
.
4.27 MJ
3.43 kJ
45.72 mJ
543.63 J