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...Advanced fluid mechanics solution to prob quiz fall ain s this device is a very clever simple design that yields information about exhalation pressure and volume flow rate with one single measurement blowing into the tube for few seconds raises interior p moves piston outward which because of spring extension also open slit area increases until reaches an equilibrium displacement x let inside be inlet velocity bev q r since outflow wx at small compared inflow v mouth thus everywhere negligible velocityv applying bernoulli equation from point in jet just outside where atmospheric gives force balance on essentially static during implies kx or mass conservation further vwx inserting k equations give as functions some comment despite numerous questions whether would include momentum theorem all answered negative both verbally via e mail large fraction class went directly no successfully problem does not lend itself easily being solved by ask tutorials whenever you do use cv approach indica...