An experimental tungsten light bulb filament has a length of 5 cm and a diameter of 0.074 cm. the filament is basically just a wire that heats due to resistance to electrical current. the ends of the wire are not exposed. the total filament emissivity is 0.300 and its temperature is 3068 k. calculate the power emitted by the lamp in watts. note: required precision is 1%.

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?