Why is my butthole soo spicy

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)

Compute the pressure drop of 30°c air flowing with a mean velocity of 8 m/s in a circular sheet-metal duct 300 mm in diameter and 15 m long. use a friction factor, f 0.02, and pair = 1.1644 kg/m a. 37.26 pa b. 25.27 pa n c. 29.34 pa d. 30.52 pa

Consider a spherical container of inner radius , outer radius r2, and thermal conductivity k. express the boundary condition on the inner surface of the container for steady one-dimensional conduction for the following cases: (a) specified temperature of 50°c, (b) specified heat flux of 30 w/m2 toward the center, (c) convection to a medium at t with a heat transfer coefficient of h