Agas with a specific heat of y and gas constant of r in a large tank of volume v is discharged through a convergent nozzle of exit area ae. at time = 0, the gas in the tank has an initial pressure pi and an initial temperature ti. assuming the flow through the nozzle is steady, one-dimensional and isentropic with critical conditions at the exit, find the time required to "blow down" the tank isentropically from the initial pressure pi to the final pressure pf.

Afour cylinder four-stroke in-line engine has a stroke of 160mm, connecting rod length of 150mm, a reciprocating mass of 3kg and its firing order is 1-3-4-2. the spacing between cylinders is 100mm. i. show that the engine is in balance with regard to the primary inertia forces and primary 3. a and secondary inertia couples. li determine the out of balance secondary inertia force ii. propose ways of balancing this out of balance force and discuss the challenges that will arise