سیال حرکیات

The equation of continuity for an incompressible fluid says:

• 1 A v is constant
• 2 P v is constant
• 3 A + v is constant
• 4 A / v is constant

Water flows through a pipe of area 4 cm2 at 2 m/s into a section of area 2 cm2. What is the new speed?

• 1 8 m/s
• 2 1 m/s
• 3 4 m/s
• 4 2 m/s

Bernoulli's principle says that where the speed of a fluid is higher, the pressure is:

• 1 Lower
• 2 Infinite
• 3 Higher
• 4 The same

Viscosity of a liquid generally:

• 1 Decreases with temperature
• 2 Increases with temperature
• 3 Is not affected
• 4 Becomes zero when heated

An aeroplane wing gets lift because air above it moves:

• 1 Backwards
• 2 At the same speed
• 3 Slower, with higher pressure
• 4 Faster, with lower pressure