Technician A says that the most efficient method of EVAP system leak detection is introducing smoke under low pressure from a machine specifically designed for this purpose. Technician B says that nitrogen gas pressurization uses nitrogen gas under a very low pressure (lower than 1 psi) in the fuel system; you listen for escaping air with amplified headphones. Who is correct?

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

True or false (explain) (110)[111] is a slip system in bcc metals . the {111} family in fcc contains 8 planes. resolved shear stress (rss) in single crystals is just related to the applied stress. critical resolved shear stress (crss) in single crystal metals is direct proportional to the number of defects in the structure