Abeka Physics test 2

Hydrostatics

The study of liquids at rest

1.013 x 10^5 bar

Not a value of standard atmospheric pressure

Newton (N)

Not a unit of pressure

It Increases

If the voltage is directly proportional to current and the current increases, what happens to the voltage?

Water head

The distance below the highest level of water in a closed system

Pascal's principle

A hydraulic device functions based on this

Nitrogen

The most abundant gas in the universe

Viscosity

The reluctance of molecules to flow because of their attraction to other like molecules and to the walls of their container

Meniscus (be aware of the spelling! The multiple choice tries to trick on the spelling of meniscus)

The curved surface of a liquid inside a small tube

Gravity

Does not contribute to the rise of water in a small tube

Charle's law

Concerned only with the proportionality between volume and temperature at a constant pressure

6.022 x 10^23

Avogadro's number

Pneumatic device

A device that transports air or is driven by air pressure

Archimedes' principle

True for all fluids

Aneroid barometer

Does not use a liquid

The pressure will increase

If a gas inside a rigid, solid steel container is heated to 350 K

Increase

If the diameter of a pipe is halved, the rate flow of the liquid inside it will

Stress

A deformative force per unit cross-sectional area

Elastic limit

The point beyond which a stretched substance will not return to its original lengthy

Plasticity

The maximum amount of relative deformation that may be permanently placed upon an object

Fluid

Any substance capable of flowing

Cohesion

The attractive force between like molecules

Bernoulli's

The principle that states lateral pressure decreases as a fluid's velocity increases

Entrainment

Using a fluid stream to catch up and carry another fluid

Avogadro

The man who stated, "At the same temperature and pressure, two gases of the same volume have the same number of molecules."

Hydraulic device

Uses a confined liquid to multiply force

Resilience

The amount of deformation required to bring a material to its elastic limit

Rolling

When a material is shaped by being pressed between heavy rollers, the material has undergone this mechanical process

Elasticity

A material that can recover its original shape after deformation displays this property

Shorter

Liquid ejected from an orifice at the bottom of a container will travel a FARTHER distance than liquid coming from an orifice at the middle of a container

True

The shape of a container DOES NOT affect the pressure on the bottom

Different

The lateral pressure on a dam is THE SAME at all depths

True

In reality, nature permits a vacuum

Manometer

A BAROMETER is a laboratory device which is used to measure the pressure of a gas sample

P = pgh

The law of liquid pressure

Define force or pressure

A force is any push or pull. Pressure is a force per unit area

Explain how surface tension creates spherical droplets of water

Because of surface tension, water pulls itself into the shape with the least possible surface area; that shape is a sphere

What two factors affect air pressure? What cause atmospheric pressure?

Air pressure is affected by the quantity of air and the temperature of that air. Atmospheric pressure is caused by the pull of gravity upon the molecules of the air

Explain how a siphon works

A siphon is a tube connecting higher and lower ranks of liquid. When a partial vacuum is created in the tube, the liquid is pushed by atmospheric from the higher tank into the tube and then pulled by gravity into the lower tank.

Define three of the four main points on a typical graph of stress vs. strain for a solid

1) the proportional limit is when the restorative force in a solid is no longer a linear function of elongation

2) the elastic limit is the maximum stress the material can sustain without being permanently deformed

3) the ultimate tensile strength is the maximum stress the material can sustain without breaking

4) the breaking points represents the maximum strain tolerated by a solid; further stressing will cause the object to break

v2 = 23 m/s (use the equation A1V1=A2V2

What is the velocity of water at the nozzle of a 50. cm^2 fire hose if the city mains are 254 cm^2 in area and if the velocity of water in the mains is 4.5 m/s?

Fs = 11 lb (use Al/As=Fl/Fs)

A man has a hydraulic jack to lift his car. If the smaller piston has an area of 0.44 cm^2, and the larger piston an area of 28 cm^2, how much force will the man have to exert on the smaller piston in order to lift one corner of the car which weighs 700. Lb?

n = 0.85 mol (use PV=nRT)

How many moles of O2 gas are in a 5.0 L container at 4.0 atm and 288 K?

Y = 3.8 x 10^10 Pa (use F/A = Y• delta l/length original

What is the value of Young's modulus for a substance 0.20 m long and 7.85 x 10^-9 m^2 in cross-sectional area if it stretches 0.010 m when a force of 15.0 N is applied?

Delta x (change in distance or length) = 7.14 x 10^-6 m (use F/A= S• delta (change in) x/d

How much deformation is produced in a brass nail 2.00 mm^2 in a cross-sectional area when a wall lamp weighing 100. N is hung from it? The lamp rests on the nail head which is 0.005 m from the wall and brass has a shear modulus of 3.5 x 10^10 N/m^2