An electric furnace is to melt 40 kg of aluminium/hour. the initial temperature of aluminium is 32°c. given that aluminium has specific heat capacity 950 j/kg k melting point 680*c, latent heat of fusion 450 kj/kg, the efficiency of furnace is 85% and cost of energy is 20 cents/kwhr calculate: (a) power required (b) the cost of operating the furnace for 30 hours

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?