It is necessary to fabricate an aligned and discontinuous glass fiber-epoxy matrix composite having a longitudinal tensile strength of 1200 mpa (175,000 psi) using a 0.36 volume fraction of fibers. compute the required fiber fracture strength assuming that the average fiber diameter and length are 0.015 mm (5.9 × 10-4 in.) and 5.0 mm (0.20 respectively. the fiber-matrix bond strength is 80 mpa (11,600 psi), and the matrix stress at composite failure is 6.55 mpa (950 psi). entry field with correct answer 3539 mpa

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.

An air conditioning system consist of a 5 cm diameter pipe, operating at a pressure of 200 kpa. the air initially enters the pipe at 15°c with a velocity of 20 m/s and relative humidity of 80%. if the heat supply throughout the process is 960 w, determine the relative humidity and the temperature at the outlet

Which of the following ziegler nichols tuning methods the response of the controller to a step input should exhibit an s-shaped curve? a)-open loop mode b)-closed loop mode c)-both modes (open & closed) d)-none of the modes (open & closed)