## This is a Free Service provided by Why Fund Inc. (a 501 C3 NonProfit) We thank you for your donation!

(1. Click on the course Study Set you wish to learn.) (2. If you wish you can click on "Print" and print the test page.) (3. When you want to take a test...click on anyone of the tests for that Study Set.) (4. Click on "Check Answers" and it will score your test and correct your answers.) (5. You can take all the tests as many times as you choose until you get an "A"!) (6. Automated college courses created from lecture notes, class exams, text books, reading materials from many colleges and universities.)

New

## Long-Term Learning

Learn efficiently and remember over time.

## Start Long-Term Learning

Get personalized study reminders at intervals optimized for better retention.
Track your progress on this set by creating a folder
Or add to an existing folder

## Add this set to a folder

• ### Fluid

a nonskid state of matter in which the atoms or molecules are free to move past each other, as in a gas or a liquid

### Equation for mass density

mass density=mass/volume

### Mass Density

the concentration of the mass of an object, measured in mass per unit volume of a substance

### Buoyant Force

the upward force exerted by a liquid on an object immersed in or floating on the liquid

### magnitude of buoyant force=_____ of ___ _____

weight, fluid, displaced

volume

mass, volume

### Solids and liquids tend to be almost ______, meaning that their density changes very little with changes in pressure

incompressible

afloat

### Pressure

the magnitude of the race on a surface per unit area

force, area

fluid

### What is Pascal's Principle?

Pressure applied to a fluid in a closed container is transmitted equally to every point of the fluid and to the walls of the container

depth, fluid

### Absolute pressure= ______ pressure+(density*___-___ acceleration)

atmospheric, free

### Ideal Fluid

a fluid that has no internal friction or viscosity and is incompressible

### What is the continuity equation?

areaspeed in region1=area speed in region 2

area

### What is Bernoulli's Principle?

the pressure in a fluid decreases as the fluid's velocity increases

ex.) as air flows around an airplane wing, air above moves faster than air below, producing a lift

fluid, gases

### What is the relationship between liquid pressure and depth of a liquid? Between liquid pressure and density?

liquid pressure increases with depth; it increases with density

### How does water pressure 1 meter below the surface of a small pond compare with water pressure 1 meter below the surface of a huge lake?

they are equal

### If you immerse a tin can with a small hole in it in water so that water spurts through the hole, what will be the direction of water flow where the hole is?

perpendicular to the surface of the can

### Why does the buoyant force act upward for an object submerged in water?

there is a greater pressure against the bottom

same

### Why does the buoyant force on submerged objects not act sideways?

pressure of each side is the same

### the upward force that acts in the opposite direction of gravity

Buoyancy Force

sink

### When the weight is equal to the buoyancy force, the submerged object will?

remains at any level

### When the weight is less than the buoyant force, the object will?

rise to the surface and float

displaced

### What are the 3 simple rules when it comes to sinking and floating?

1) an object more dense than the fluid in which it is immersed sinks
2) an object less dense than the fluid sinks
3) an object with equal density to the fluid neither sinks nor floats

### Is the weight of the displaced water or the the weight of the submerged object the buoyant force when an object is completely submerged?

the weight of the displaced water

Pascal; Pa

### After a long class, a physics teacher stretches out for a nap on a bed of nails how is this possible?

The weight of the teacher would be spread out across the nails rather than all centered on one, preventing the nails going through the body of the teacher.

### If an inflated beach ball is placed beneath the surface of a pool of water and released it shoots upward, out of the water. use archimedes' principle to explain why...

Archimedes principal is: "The upward buoyancy force is equal to the magnitude of the weight of fluid displaced by the body". So, the upwards force on the beach ball is equal to the weight ot the water idisplaced when pushed underwater.

### Moving fluids can exhibit ________ (smooth) flow or______ (irregular) flow

laminar, turbulent

ideal fluid

A1v1 = A2v2

### The continuity equation results from ________ of ______

conservation, mass

flow

### Solid objects only exert pressure in one direction.

Liquids and gases exert pressure equally in all directions.

high, low

10 N

### more internal pressure means

less speed and kinetic energy

### What is the SI unit of mass density?

kilograms per cubic meters

### Buoyant force acts in the _____ ______ of the force of gravity

opposite direction

density

depth

### Is a large amount of pressure always caused by a large force? Explain your answer.

No. Pressure is force per unit area: p=f/a. Thus it does not require a large force to produce a large pressure.

### When drinking through a straw, you reduce the pressure in your mouth and the atmosphere moves the liquid. Could you use a straw to drink on the moon?

No, a straw will not function on the Moon because there is no atmosphere.

### Steel is much denser than water. How, then, do steel boats float?

Because of the pressure of the water, forces act on the boat. The resulting force is the buoyancy force, which pushes the boat up.

### Will a ship ride higher in an inland freshwater lake or in the ocean? Why?

rides higher in salt water. Because the density of the water is higher. Which means that the weight of the displaced water is higher, so the ship needs less displaced water to balance it's weight.

### Explain why balloonists use helium instead of air in balloons.

Since pure Oxygen is heavier than air, a balloon filled with Oxygen would sink because of its heavier contents plus the weight of the balloon

### Astronauts sometimes train underwater to simulate conditions in space. Explain why.

because of buoyancy in water your body comes up stimulating weightlessness.... hence astronauts train underwater

### Lead has a greater density than iron, and both metals are denser than water. Is the buoyant force on a lead object greater than, less than, or equal to the buoyant force on an iron object of the same volume?

The two are equal because the buoyant force depends only upon the density and volume of the liquid that is displaced.

Example: