A weightlifter lifts 250 kg mass 0.5 meters above hus head how much PEg does the mass have

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody

Arigid tank contains 10 kg of air at 137 kpa (abs) and 21°c. more air is added to the tank until the pressure and temperature rise to 242 kpa (abs) and 32°c, respectively. determine the amount of air added to the tank. [r-0.287 kj/kg k]