A380-l tank contains steam, initially at 400oc, 3 bar. a valve is opened for 30 seconds and steam flows out of the tank at a constant mass flow rate of 0.005 kg/s. during steam removal, a heater maintains the temperature within the tank constant. determine final mass remaining in the tank, in kg, and the final pressure in the tank, in bar.

In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. the cylinder begins to rotate about a vertical axis. then the floor on which the passengers are standing suddenly drops away! if all goes well, the passengers will “stick” to the wall and not slide. clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. part a what is the minimum rotational frequency, in rpm, for which the ride is safe? express your answer using two significant figures. f f = rpm