PASS Content Standard 3.1 All energy can be considered to be either kinetic, which is the energy of motion; potential, which depends on relative position; or energy contained by a field, such as electromagnetic waves.

A force that acts over a certain area. Pressure = Force Area

Pressure - 2 min

Exert pressure because of the motion of their particles.

Exert pressure because of the motion of their particles.

What is happening?

Air molecules inside a basketball press against the material. The more air in the ball, the less it will compress and the higher it will bounce. Can you dribble a ball with no air?

Barometers Measure Air Pressure

The pressure exerted by air at sea level is N/cm 2

Atmospheric pressure is usually reported by the “weatherman” in inches of mercury “Normal” atmospheric pressure is in Hg

Is that a lot? inches of mercury

Is that a lot? inches of mercury

Weather - 27 min

Describe the characteristics of a low pressure air mass

Describe the characteristics of a high pressure air mass

What is a weather "front"?

How does this picture relate to atmospheric pressure?

The force of a fluid that pushes up on an object in a fluid.

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

If buoyant force is greater than the weight of the object, the object will rise in the fluid.

If buoyant force is less than the weight of the object, the object will sink 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 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 g F 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 t P 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 t G 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 between the ball and the bat lasts only about 1 / 1000 sec.

The ball distorts to about half its original diameter when it contacts the bat.

The decision to swing has to be made within 0.04 seconds.

Swing 1 / 100 second too soon and the ball goes foul down the left field side.

Swing 1 / 100 second too late and the ball goes foul down the right field side.

An aluminum bat can hit a baseball 30 feet farther than a wooden 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 bounces off the bat faster than the cork can store energy that might be given back to the ball.

These two factors combine to make a corked bat hit the ball less distance the 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 the spin 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 - but increases backspin to 2643 rpm. 455 feet

This increases the lift of the batted ball. 455 feet

What is the mass of a baseball?

Why does the ball slow down after leaving the pitcher's hand?

What is the maximum distance a batted baseball should be able to travel?

A baseball travels 400 feet at sea level, how far would the same baseball travel at an altitude of 5000 feet?

Why do fly balls travel farther when the humidity is low?

During a pitch, where does a curveball do most of its curving?

What direction does a curveball break?

Does a corked bat hit a baseball farther than a normal wooden bat?

Why can a curveball be hit farther than a 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 of 2 kg/cm 2 in the first cylinder is transmitted through the fluid to the second cylinder.

Since cylinder #2 has 5 times the area of the first cylinder, the pressure is multiplied 5 times.

The greater the difference in size between the two cylinders, the more the force is multiplied.

Energy - 1 min

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/s 2 )

GPE = mgh

The units are Joules kilogram meters / s 2

Potential Energy - 5 min

Chemical Potential Energy - energy due to condition

mgh = 1 / 2 mv 2

Energy an object has because of its motion.

KE = 1 2 MV 2

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

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

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 are 5 types mechanical heat chemical electromagnetic nuclear

Forms of Energy - 1 min

There are 5 energy types Mechanical energy is associated with motion.

There are 5 energy types Heat energy is the internal motion of particles.

There are 5 energy types Chemical energy bonds atoms and molecules together.

There are 5 energy types Electromagnetic energy is contained in moving electric charges.

There are 5 energy types Nuclear energy holds the atomic nucleus together.

Atomic Bombs - 4 min

E = energy in Joules m = mass in kilograms c = speed of light (300,000 km/s)

Think of matter and energy as two forms of the same thing that can be converted from one to another.

Splitting of a heavy atomic nucleus

Fusing two or more light-weight atomic nuclei

Nuclear Reactions - 11 min

Man's first atomic explosion July 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 charges on an object.

Lightning - 3 min

Static Electricity - 6 min

Conduction Friction 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 changes direction periodically

All AC electricity produced 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 to change electric voltage.

Transformers - 1 min

When electricity is supplied to the primary coil, it magnetizes the core and produces a voltage in the secondary coil.

The voltage produced depends on the ratio of the number of 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" transformer reduces voltage for the final time.

Amps

Find out WHY a fuse blows before replacing

Why do some meters have 5 dials and other meters have only 4?

1

1

13

13

136

136

1364

1364

13641

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 t S 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 t S 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 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 t P 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 potential difference between two points

A measure of the amount of current flowing past a given point 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

E l e c t r i c P o w e r C a l c u l a t i n g: W a t t s = V o l t s X A m p s

E l e c t r i c P o w e r C a l c u l a t i n g: E n e r g y = P o w e r X T i m e

What causes this force?

A force of attraction or repulsion due to an arrangement of 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 poles attract.

Each of these three magnets repels the other two. How could you arrange the magnets so that each attracts the other two instead?

A triangle arrangement brings the north pole of each magnet to the south 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 particles given off by the sun.

The Earth’s magnetosphere extends 37,300 miles from the Earth on the side facing the sun. And much farther on the side away from the sun.

A compass is used to detect the Earth's magnetic field.

Earth's Magnetic Field - 3 min

Collision of charged particles from the Sun with charged particles in the 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 Index 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 an electromagnet is increased by wrapping the coil around an iron core.

The magnetic field is active only when the current is flowing. The more coils of wire, the stronger magnet.

When a conducting wire cuts across magnetic lines of force, a current is produced.

Convert electric energy into mechanical energy.

split rings magnet

DC motors - 5 min

Convert mechanical energy into electrical energy.

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. A cylindrical mass and bucket are suspended from a spring scale above a beaker with an overflow spout. Note the scale reading.

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. Submerge the mass by raising the beaker. Pour the water from the catch beaker into the hanging bucket to return to the original scale reading.