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?

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.

Fluids at rest possess no flow energy. a)- true b)- false

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.