pass content standard 3.1

PASS Content Standard 3.1

All energy can be considered to be eitherkinetic, which is the energy of motion;potential, which depends on relativeposition; or energy contained by a field,such as electromagnetic waves.

A force that acts over a certain area.

Pressure = Force

Area

Pressure - 2 min

QuickTime™ and aSorenson Video 3 decompressorare needed to see this picture.

Exert pressure because of the motion of theirparticles.

What is happening?

Air molecules inside a basketballpress against the material.

The more air in the ball, the less it will compress and the higher it will bounce.

Can you dribblea ball with no air?

BarometersMeasure

Air Pressure

The pressure exerted by air at sea levelis 10.13 N/cm2

Atmospheric pressureis usually reported bythe “weatherman” in

inches of mercury

“Normal” atmosphericpressure is

29.92 in Hg

Is that a lot?

29.92 inches of mercury

Weather - 27 min


Describe thecharacteristicsof a low pressure air mass

Describe thecharacteristicsof a high pressure air mass

What is aweather "front"?

How does this picture relateto atmospheric pressure?

The force of a fluidthat pushes up onan object in a fluid.

If buoyant force isequal to the weight of the object, the object will be suspended inside the fluid.

If buoyant force isgreater than theweight of the object,the object willrise in the fluid.

If buoyant force isless than the weight of the object,the object willsink in the fluid.

Archimedes Principle states that the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object.

The pressure in a moving stream of fluid is less than the pressure in the surrounding fluid.

The Bernoulli's Principle keeps airplanes in the air.

Flight - 4 min


F o r c e s a c t i n g o n a n a i r p l a n e

T h r u s t f o r w a r d f o r c e p r o d u c e d b y t h e e n g i n e .

D r a gF r i c t i o n a s t h e p l a n e m o v e s t h r o u g h t h e a i r .

L i f tP r o d u c e d b y u n e q u a l a i r p r e s s u r e s o n t h e w i n g s u r f a c e s .

W e i g h tG r a v i t y p u l l i n g t h e p l a n e d o w n .

The Wright Brothers - 8 min


Reverse Engineering - 12 min


The bat exerts about 8000 pounds of force on the ball.

Contact betweenthe ball and thebat lasts onlyabout 1/1000 sec.

The ball distortsto about half itsoriginal diameterwhen it contactsthe bat.

The decision toswing has tobe made within0.04 seconds.

Swing 1/100 second toosoon and theball goes foul down the left field side.

Swing 1/100 second toolate and theball goes foul down the right field side.

An aluminumbat can hit abaseball 30 feetfarther than awooden bat.

In general, a baseball will curve in the same direction that the front of the ball turns.

The faster the spin,the greater the break.

A corked bat is lighter,so its swing speed is faster.

But the baseball bouncesoff the bat faster than thecork can store energy thatmight be given back tothe ball.

These two factorscombine to make a corked bat hit theball less distancethe a regular bat.

For maximum distance, hit the ball just under its center of mass.

This always adds backspin to the ball -providing lift.

A batted ball should be able to travel no farther than 545 Feet.

A 94 mph fastball is thrown with 1910 rpm backspin.

Hitting the fastball changes thespin direction - provides 1827

rpm backspin.

442 feet

This reduces the lift of the batted ball.

442 feet

A 78 mph curveball is thrown with 1910 rpm topspin.

Hitting the curveball does not change the spin direction - butincreases backspin to 2643 rpm.

455 feet

This increases the lift of the batted ball.

455 feet

What is themass of abaseball?

Why doesthe ballslow downafter leavingthe pitcher'shand?

What is themaximumdistance abatted baseballshould be ableto travel?

A baseball travels400 feet at sea level,how far would thesame baseballtravel at an altitudeof 5000 feet?

Why do flyballs travelfarther whenthe humidityis low?

During apitch, wheredoes a curveballdo most ofits curving?

What directiondoes a curveballbreak?

Does acorked bathit a baseballfarther than a normal wooden bat?

Why can acurveball be hit farther thana fastball?

Fastball: Hold the ball near the ends of your fingers and throw with a normal overhand delivery. The ball should roll off your fingers with a backwards spin (it will tend to rise). Outfielders usually throw the ball this way because the rising action allows them to throw it considerably farther.

Curveball: "Choke" the ball (wedge it down between your thumb and forefinger), and cock your wrist to the left; the ball snaps down and to the right on release. The resulting pitch should drop and curve to the left.

Screwball: Throw the ball like a curveball, but reverse the wrist action and spins. Cock the wrist initially to the right and "turn the ball over" to the left as you throw it. The ball should break down and to the right.

Slider: Throw the ball like a football pass, with the wrist cocked at a 90 degree angle . The ball should curve slightly down and to the left.

End Baseball Physics

A pressure of2 kg/cm2 in thefirst cylinder istransmittedthrough the fluid to the secondcylinder.

Since cylinder #2has 5 times thearea of the firstcylinder, thepressure ismultiplied 5 times.

The greater thedifference in size between the twocylinders, themore the forceis multiplied.

Energy - 1 min

QuickTime™ and aSorenson Video decompressorare needed to see this picture.

Energy stored in an object due to its position.

Gravitational potential energy,GPE, is dependent on an object’s height above the surface of the earth.

GPE = weight (N) X height (m)

weight = mass (kg) X g (9.8 m/s2)

GPE = mgh

The units are Joules

kilogram meters / s2

Potential Energy - 5 min


Chemical Potential Energy -

energy due to condition

mgh = 1/2 mv2

Energy an object has because of its motion.

KE = 12 MV2

Potential energy can be changed into kinetic energy and kinetic energy can be changed into potential energy.

Law of Conservation of Energy - 4 min


Useful Energy Changes - 3 min


There are5 types

mechanicalheatchemicalelectromagneticnuclear

Forms of Energy - 1 min


There are5 energy types

Mechanical energy is associated with motion.


Heat energy is the internalmotion of particles.


Chemical energy bondsatoms and moleculestogether.


Electromagnetic energyis contained in moving electric charges.


Nuclear energy holds the atomic nucleus together.

Atomic Bombs - 4 min


E = energy in Joulesm = mass in kilogramsc = speed of light (300,000 km/s)

Think of matter and energy as twoforms of the same thing that canbe converted from one to another.

Splitting of aheavy atomic nucleus

Fusing two or morelight-weight atomic nuclei

Nuclear Reactions - 11 min


Man's first atomic explosionJuly 16, 1945, at 5:29:45 a.m.

"Little Boy" was dropped on Hiroshima, Japan on August 6, 1945.

It weighed about 9,000 pounds and had an explosive force of

about 20,000 Tons of TNT

Hiroshima after the bomb.

"Fat Man" was dropped on Nagasaki, Japan on August 9, 1945.

It weighed about 10,000 pounds and had an explosive force of

about 20,000 Tons of TNT

Nagasaki after the bomb.

Conservation of energy - 4 min


Electricity is energy associated with charged particles as they move from place to place

Like charges repel

Opposite charges attract

Unequal chargeson an object.

Lightning - 3 min


Static Electricity - 6 min


ConductionFriction

Induction

Conduction

When an object with an excess of electrons touches a neutral object, electrons are passed to the neutral object.

Conduction - 7 min


Friction

When an object whose electrons are loosely held rubs against another object, electrons are transferred to the second object.

Friction - 5 min


Induction

A neutral object acquires a charge from a charged object close by without contact being made.

Induction - 12 min


Current flows in only one direction

Batteries change chemical

energy into electrical energy.

Batteries - 2 min


Current flow changesdirection periodically

All AC electricityproduced in the U.S.is "60 cycle"electricity.

Fuel Power Plants - 3 min


There are about 110 nuclear power plants in the US

Nuclear Power Plants - 3 min


Blackout - 3 min


Transformers are used tochange electric voltage.

Transformers - 1 min


When electricity is supplied to theprimary coil, it magnetizes the coreand produces a voltage in thesecondary coil.

The voltage produced depends on the ratio of the numberof turns in each coil.

The primary coil below has 10 turns, while the secondary has 2. The ratio is 5 to 1 - which means the voltage produced across the secondary will be 1/5 the voltage of the primary.

The primary coil below has 3 turns, while the secondary has 6. The ratio is 1 to 2 - which means the voltage produced across the secondary will be twice the voltage of the primary.

The "pole" transformerreduces voltagefor the final time.

Find out WHYa fuse blowsbefore replacing

Why do some meters have 5 dialsand other meters have only 4?

1 3 6 4

1 3 6 4 1

E l e c t r i c C i r c u i t s

Electric circuits - 4 min


E l e c t r i c C i r c u i t

S e r i e s

C i r c u i t

P a r a l l e l

C i r c u i t

E l e c t r i c C i r c u i tS e r i e s C i r c u i t

E l e c t r i c C i r c u i tP a r a l l e l C i r c u i t

A measure of the energy available to move electrons

The electric potentialdifference between two points

A measure of the amount ofcurrent flowing past a givenpoint in a given time.

E l e c t r i c P o w e r

• C a l c u l a t i n g:

P o w e r =

V o l t a g e X C u r r e n t



W a t t s = V o l t s X A m p s



E n e r g y = P o w e r X T i m e

1.000

0.200

0.100

0.010

0.001

What causes this force?

A force of attractionor repulsion due to an arrangementof electrons.

Magnetism - 4 min


The area around a magnet where magnetic forces act.

The forces are concentrated at the end of a magnet.

Like poles repel.

Unlike polesattract.

Each of these three magnetsrepels the other two.

How could you arrange the magnets so that each attracts the other two instead?

A triangle arrangementbrings the north pole ofeach magnet to thesouth pole of the others.

Magnetic induction:

the process by which a material is made into a magnet.

During this process, atoms in a substance are aligned.

Temporary magnets:

Materials that are easy to magnetize, and loose their magnetism quickly.

Permanent magnets:

Materials that are hard to magnetize, but tend to stay magnetized.

Lodestone - 3 min


Magnetosphere: the region of the earth's magnetic field.

Extends beyond the atmosphere.

Composed of charged particlesgiven off by the sun.

The Earth’s magnetosphereextends 37,300 miles fromthe Earth on the sidefacing the sun.

And muchfarther on theside away from the sun.

A compass is used to detectthe Earth's magnetic field.

Earth's Magnetic Field - 3 min


Collision of charged particles from the Collision of charged particles from the Sun with charged particles in Sun with charged particles in the Earth’s upper atmospherethe Earth’s upper atmosphere

Collision of charged particles from the Collision of charged particles from the Sun with charged particles in Sun with charged particles in the Earth’s upper atmospherethe Earth’s upper atmosphere

Aurora Borealis

Aurora Australis

Aurora Borealis

Aurora Australis

The ultimate energy source for the polar auroras is the solar wind.

Kp

Inde

x

Date, 2004

Polar auroras go through cycles with solar activity.

Electricity and Magnetism - 3 min


Produced by a current running through a coil of wire.

The strength of anelectromagnet isincreased by wrapping thecoil around aniron core.

The magnetic field is activeonly when the current is flowing.

The more coils of wire, the stronger magnet.

When a conducting wirecuts across magneticlines of force, acurrent is produced.

Convert electricenergy intomechanicalenergy.

split rings

magnet

magnet

DC motors - 5 min


Convert mechanical energy into electrical energy.


A cylindrical mass andbucket are suspendedfrom a spring scaleabove a beaker withan overflow spout.

Note the scalereading.


Submerge the massby raising the beaker.

Pour the water fromthe catch beaker intothe hanging bucketto return to theoriginal scalereading.

pass content standard 3.1

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