A(n) 822 n crate is being pushed across a level floor by a force of 387 n at an angle of 24◦ above the horizontal. the coefficient of kinetic friction between the crate and the floor is 0.24. the acceleration of gravity is 9.81 m/s 2 .

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)