What is the gear ratio of the given train

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)

Consider airflow over a flat plate of length l = 1.5 m under conditions for which transition occurs at le = 0.9 m based on the critical reynolds number, re,e = 5 x 10. evaluating the thermophysical properties of air at 400 k, determine the air velocity. (hint: use the tables to find the properties of air)

Oxygen at 300 kpa and 400 k is in a closed system with an initial volume of 0.1 m3. is now compressed in a polytropic process, with exponent of n 1.2, to a temperature of 500 k. calculate: a) the boundary work done during the compression, in kj b) the heat transfer during the compression, in kj