A 1'x1' square concrete pile is embedded 20 feet in clay with an undrained shear strength of 2,800 psf. Based on the LaTeX: \alphaα-method and LaTeX: \alphaα-values of Terzaghi et al. (1996), what is the ultimate shaft friction, Qs in pounds? Use pa=2,000 psf.

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

When at a point two solid phase changes to one solid phase on cooling then it is known as a) eutectoid point b) eutectic point c) peritectic point d) peritectoid point

To save energy, the air supply to a 2000 ft office has been shut off overnight and the room temperature has dropped to 40°f. in the morning, the thermostat is reset to 70°f and warm air at 120 f begins to flov in at 200ft'/min. the air is well mixed within the room, and an equal mass flow of air at room temperature (changing with time) is withdrawn through a return duct. the air pressure is nearly 1 atm everywhere. ignoring heat transfer with the surroundings and kinetic and potential energy effects, estimate how long it takes for the room temperature to reach 70°f. plot the room temperature as a function of time.