Consider an ideal turbojet at flight conditions: To =220 K, PO = 20 kPa, and Mo= 0.8. Calculate and plot: 1) the specific thrust, 2) f, and 3) ISP versus the compressor stagnation pressure ratio (πc). Perform calculations for Tt, A=1600 K and 1800 K and for πc from 1 to 50. The fuel heat of combustion is hf= 42,800 kJ/kg. What πc maximizes thrust at the two peak stagnation temperatures?

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?