Hydrogen gas (density = 1.165 kg/m^3 ) is stored at 25°C in a permeable cylindrical container which has an outer diameter of 0.25 m, a wall thickness of 5 mm and a length of 2 m. The cylinder is exposed to ambient air.
If the container is charged to an initial pressure of 5 bars, at what would be the mass diffusion rate (in kg/s) of hydrogen through the cylinder? Hydrogen solubility in the container is 0.5X10^(-3) kmol/m^3 bar and diffusivity at 293K and 1 bar is 0.4x10^(-13) m^2 /s.

A-mn has a cubic structure with a0 0.8931 nm and a density of 7.47 g/cm3. b-mn has a different cubic structure, with a0 0.6326 nm and a density of 7.26 g/cm3. the atomic weight of manganese is 54.938 g/mol and the atomic radius is 0.112 nm. determine the percent volume change that would occur if a-mn transforms to b-mn.

Acircular aluminum shaft mounted in a journal is shown. the symmetric clearance gap between the shaft and journal is filled with sae 10w-30 oil at t 30°c. the shaft is caused to turn by the attached mass and cord. develop and solve a differential equation for the angular speed of the shaft as a function of time.

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?