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35 Cards in this Set
- Front
- Back
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What is the formula for density? |
Rho=mass/volume |
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What is the units for density? |
Kilograms per cubic metre. |
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What is the densest material on earth? |
Osmium. |
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What is the specific gravity of a material? |
The ratio of its density to the density of water. |
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What two environmental factors does density depends upon? |
Temperature and Pressure. |
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What is the formula for pressure in a fluid? |
Pressure = Force/Area |
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What is the formula for pressure in a fluid of uniform density? |
pressure = pressure originally + rho*g*height |
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What is true about the pressure at any two points at the same level in a fluid? |
It is the same. The shape does not matter. |
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What happens to the pressure at the bottom if you increase the pressure on the top surface of a container? |
It will increase by the same amount. |
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What is Pascal's Law? |
Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel. |
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What is the formula for F2? |
F2 = (A2/A1)*F1 |
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What is true about a car tire if the pressure inside it is the same as atmospheric pressure? |
The tire is flat. |
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What is the excess pressure above atmospheric pressure called? |
Gauge pressure. |
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What is the total pressure called? |
Absolute pressure. |
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What is Archimedes's Principle? |
When a body is completely or partially immersed in a fluid, the fluid exerts an upward force on the body equal to the weight of the fluid displaced by the body. |
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How does surface tension occur? |
The water molecules on the surface exert attractive forces on one another. |
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What is true about the surface area of a membrane under tension? |
It tends to minimise its surface area. |
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What is the term for internal friction in a fluid? |
Viscosity. |
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What is the path of an individual particle in a moving fluid called? |
A flow line. |
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If the overall flow pattern does not change with time, what is the flow called? |
Steady flow. |
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What is a streamline? |
A streamline is a curve whose tangent at any point is in the direction of the fluid velocity at that point. |
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What is laminar flow? |
When adjacent layers of fluid slide smoothly past each other and the flow is steady. |
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What is turbulent flow? |
At high flow rates when the flow becomes irregular and chaotic. There is no steady-state pattern; the flow pattern changes continuously. |
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What quantitative relationship comes from the fact that the mass of a moving fluid doesn't change as it flows. |
The continuity equation. |
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What is the continuity equation? |
A1v1=A2v2. |
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What is the volume flow rate equation? |
dV/dt=Av |
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What is the mass flow rate? |
The mass flow per unit time through a cross section |
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What does the volume flow rate equation show? |
The flow rate has the same value at all points along any flow tube. |
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When an in-compressible fluid flows along a flow tube with varying cross-section, what must change? |
It's speed which means an element of the fluid must have an acceleration. |
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What would happen if the pressure where the same at all points in a flow tube with varying cross sectional area? |
The net force on every element would be zero. |
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What is Bernoulli's equation? |
p1+rho*g*y1+0.5*rho*(v1)^2 = p2+rho*g*y2+0.5*rho*(v2)^2 |
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What does Bernoulli's equation show? |
The work done on a unit volume of a fluid by the surrounding fluid is equal to the sum of the changes in kinetic and potential energies per unit volume that will occur during the flow. |
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When is Bernoulli's equation valid? |
When the fluid is incompressible, steady flowing and had no internal friction (viscosity). |
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What is the boundary layer of a viscous fluid? |
The layer in which the fluid the nearly at rest with respect to the surface. This makes a viscous fluid cling to surfaces making it harder to get off. |
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How do you ensure the flow of a viscous liquid? |
Apply a greater pressure at the back of the flow than at the front. |
