Question

If the mouthpiece diameter is 0.5mm, what is the length of the mouth​

Answer 1

Pressure force on mouthpiece  =  pressure � area of mouthpiece = ωH α

Where,

ω = Weight density of liquid (ρg)

H = Height of liquid above the mouthpiece

α = Area of mouthpiece

αc = Area at vena contracta

V = flow velocity

Mass of liquid flowing per sec = ρ αc V

We know,

Momentum = mass X velocity

Rate of change of momentum = mass of liquid flowing/sec � change of velocity

                                                  = (ρ αc V) � (final velocity−initial velocity)

Placing,

Initial Velocity = 0

Final Velocity = V

Since weight density ω = ρg