Chapter 15 - Fluid Motion

Question 1

What makes a fluid compressible?

Answer 1

If the distance between their molecules is great enough

Question 2

Fluid

Answer 2

Matter that readily flows due to external forces: liquids & gases

Question 3

What is Archimedes’ principle?

Answer 3

The weight of the fluid displaced is equal to the buoyant force acting on the object.

Question 4

Where is the center of buoyancy (CB) placed?

Answer 4

It is above the center of mass (CM)

Question 5

Is buoyancy a conservative or non-conservative force?

Answer 5

It’s non-conservative

Question 6

How is steady flow different from unsteady?

Answer 6

Steady flow is where the fluid motion is constant throughout a section

Question 7

Are mass and energy conserved in fluid motion?

Answer 7

Yes, they are both conserved and are modeled using the continuity and energy equations.

Question 8

Viscosity

Answer 8

A kind of fluid friction between a fluid and its surface contact

Question 9

Bernoulli’s Principle

Answer 9

For a fluid to pass through a smaller area it has to be going at a faster speed.
This means that a fluid travelling at a higher speed is going to have lower pressure as both sides of the fluid have to be equal.

Question 10

Buoyancy

Answer 10

The force which opposes the weight of an object that is in a fluid. The greater the density of the fluid or volume of object displaced, the greater the buoyant force is.

Question 11

Gauge Pressure

Answer 11

The pressure that is measured relative to atmospheric pressure.

Meaning that atmospheric is taken as the 0 point and gauge pressure is the value measured on top of atmospheric pressure.

Question 12

Absolute Pressure

Answer 12

The sum of the gauge and atmospheric pressure acting on an object.