A metal sphere of radius 3cm made of brass is heated from 30°C to 100°C , Calculate the initial and final volume of the
metal sphere (Iinear expansivity of brass =0.000019k-¹ and volume of sphere =⁴/3 πr³

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)