If the ASTM Grain size number of one piece of metal is 2 and the ASTM Grain size number of another piece of metal is 8, in which piece would you expect grain boundary diffusion to be most significant?

a. They will both be the same
b. The one with an ASTM Grain size of 2.
c. The one with an ASTM Grain size of 8.

Find the minimum film thickness for a journal bearing with the data below. shaft diameter, d-50 mm, clearance ratio, cdratio? 0.001, shaft speed, n 2000 rpm; bearing length. i 200 mm; eccentricity ration, ? -0.55. ( note, cdratio-ca/d) the minimum film thickness is um

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?

Aspherical thermocouple measurement errors a spherical thermocouple made of constantin transfer coefficient between the gas and the thermocouple is h used to measure the temperature of a gas. the heat 400 w/m2 k. calculate the maximum diameter d of the thermocouple if the thermocouple's measurement error should be w 23 within 5% of the initial temperature difference in 5 seconds. for constantin, k 8920 kg/m3, and c 410 j/kg. k.