A120 cy per hr maximum output pump is used to place the concrete for a 200 cy slab. the concrete is supplied by 8 cytransit-mix trucks arriving to the site on 12 min intervals. the concrete batch plant is located 5 miles from the site. averagetruck speed is 30 mph. each transit-mix truck takes, on average, 10 min to discharge. the placement crew size is 7 workers. average worker output is 5 cy of concrete per hr. (a) how long will the operation take? (b) how can the operation bereorganized more effectively?

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Steam enters a converging nozzle at 3.0 mpa and 500°c with a at 1.8 mpa. for a nozzle exit area of 32 cm2, determine the exit velocity, mass flow rate, and exit mach number if the nozzle: negligible velocity, and it exits (a) is isentropic (b) has an efficiency of 94 percent

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?