Thirty Joules of energy are transferred out of a system. The energy is lost through heat, mechanical, and electrical energy. If mechanical energy took up 10 J and electrical energy took up 5 J, how many Joules were lost through heat energy? OPTIONS

5 J

15 J

30 J

45 J

An ideal otto cycle has a compression ratio of 10.5, takes in air at 90 kpa and 40°c, and is repeated 2500 times per minute. using constant specific heats at room temperature, determine the thermal efficiency of this cycle and the rate of heat input if the cycle is to produce 90 kw of power.