The reynolds number is a dimensionless quantity used in fluid mechanics. it is defined as: where d is the pipe diameter, v is the fluid velocity, is the fluid density, and is the fluid viscosity. in american engineering units (ft, sec, lbm), what are the units of the viscosity? hint, all the units should cancel out to produce the dimensionless reynolds number.

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.