An aluminum (shear modulus = 2.8 x 10 Pa) rod is 25 mm in diameter and 50 cm long. One end is rigidly fixed to a support. What torque must be applied to twist the rod 4.5° about its longitudinal axis? A) 26 N. m B) 84 N. m C) 110 N-m D) 170 N. m

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.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false