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Write equation of continuity

• A₁V_{1 =} A₂V₂

• A₁V_{1 =} A₂V_{2 = Constant}

• AV

• ρAV

State one assumption made in deriving equation of continuity

• no friction between layers of the liquid

• The flow is calm

• The fluid is compressible

• The flow is steady

Find flow rate of a pipe whose cross-section area is 0.5m² and flowing at a velocity of 20m/s.

• 10

• 40m³/s

• 10m²/s

• 10m³/s

How do we find mass flux

• ρv

• ρVA

• ρA

• VA

Water flows steadily along a horizontal pipe at a volume rate of 8x10^-3m³s^-1. If the area of cross-section of the pipe is 20cm², calculate the velocity of the fluid.

• 4.0x10^-8 m/s

• 4.0x10^-4 m/s

• 40 m/s

• 4 m/s

Water flows steadily along a horizontal pipe at a volume rate of 8x10^-3m³s^-1. If the area of cross-section of the pipe is 20cm², calculate the velocity of the fluid.

• 4.0x10^-8 m/s

• 4.0x10^-4 m/s

• 40 m/s

• 4 m/s

The window and door of a house are both left open during a windy day. The door which opens inwards, tends to slum shut when it is slightly ajar. Explain.

• Wind blew at a low velocity from inside hence increasing pressure inside pushing the door to shut

• Wind blew at a high velocity from outside hence decreasing pressure outside causing door to shut

• Wind blew at a low velocity from outside hence increasing pressure inside pushing the door to shut

• All the above

It is dangerous to stand close to a railway line on which a fast moving train is passing. Explain.

• Train has magnets which can pull one into rails

• A strong wind blows once a train passes hence pushing one backwards which may result to injury

• As train passes at high speed, pressure around it reduces hence one can be sucked into the rails

• One can cause accident

State Bernoulli's principle as an equation

• The pressure, the kinetic energy per unit volume and the potential energy per unit volume of the fluid is a constant

• The pressure, the kinetic energy and the potential energy per unit volume of the fluid is a constant

• sum of the pressure, the kinetic energy per unit volume and the potential energy per unit volume of the fluid is a constant

  
  

• sum of the pressure, the kinetic energy per unit volume and the potential energy per unit volume of the fluid are equal

State Bernoulli's principle as an effect

• increase in speed produces a corresponding decrease in pressure

• increase in velocity produces a corresponding decrease in pressure

• increase velocity produces a corresponding increase in pressure

  
  

• Decrease in velocity produces a corresponding decrease in pressure it exerts