# Physics

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```							Physics
Force and Motion -Physics

Laws of planets motions, and electromagnetic Spectrum

1. A force acting on an object and moving it through a distance
does work on that object and changes it's kinetic energy (energy of
motion), potential energy (energy of position), or both. The ratio of
output work to input energy is the efficiency of the machine or
process and is always less than 100%. Power is the rate at which
the work is done.

Analyze and describe qualitatively the changes in potential
and kinetic energy of a person participating in an individual
sport (e.g., ski-jumping, diving, hitting a ball, and racing).

Use a simple machine such as a 10 speed bicycle to
investigate the relationship among work, power, and
efficiency. Calculate the mechanical advantage and discuss
its importance in the use of the machine.

2. Displacement, velocity, acceleration, and time are used to
describe the motion or changes in the motion of an object.

Use available data to display graphically the effect of weight,
speed, and driver response time on the stopping distance of
cars and trucks. Discuss the importance of each variable in
determining the overall stopping distance and their relevance
to safe driving.

3. Objects can have linear motion, rotational motion, or both.
Newton’s Laws can be used to predict changes in linear motion
and/or rotational motion. Momentum allows objects to remain in
motion after the applied force is removed. The Law of
Conservation of Momentum can be used to predict the outcomes of
a collision between moving objects.

Use Newton’s Laws of Motion to investigate the effect of
force on velocity, acceleration, and equilibrium of an object.
Describe the relationship between the kinetic and potential
energy of the object using narrative and/or quantitative
descriptions.

Describe different ways in which the effects of twisting
forces (torque) are used in everyday situations (e.g.,
tightening a bolt, using a screwdriver, or opening a
combination lock). Demonstrate how the magnitudes of these
torques can be altered.

Use the law of Conservation of Momentum to describe and
discuss the result of a collision between two or more objects
(e.g., players in various sports, moving vehicles).

Transformation and Conservation of Energy

Latent heat absorbtion, phase changes

1. Energy can be transformed from one form into another, but the
total energy is constant in a closed system. The amount of energy
involved in any process, and the rate at which it is generated or
consumed can be discussed qualitatively and measured. Some heat
is released or absorbed in most energy transformations.

Measure the heat released when the energy stored in fuels (or
foods) is released upon combustion. Discuss and account for
the energy balance in the process.
Determine the amount of heat required to change the
temperature or phase of a material (e.g., the latent heat of a
phase change for various materials).

2. Energy can be transferred from one place to another by gross
movement of material (e.g., wind, waterfalls, thrown ball), by
mechanical waves moving through a material medium (e.g.,
sounds, earthquakes, tidal waves), or by electromagnetic waves
(e.g., light, microwaves). The observed wavelength of a wave
depends on the relative motion of the source and the observer and
can be shorter or longer than the actual wavelength, depending on
whether the relative motion is towards the source or away from the
source respectively. This apparent change is called the Doppler
Effect.

Discuss, in terms of the properties of waves, the apparent
change in a train whistle as the train passes. Research and
discuss the application of these properties in the
measurement of distance and relative movement (e.g., of
stars, or of local weather systems).

3. Mass is converted to large quantities of energy in the processes
of nuclear fission and fusion. The energy released can be
calculated using the equation E=mc2. The total of energy and mass
is constant in these processes.

Compare the energy released from a material (e.g., 1 gm. of
hydrocarbon) burned as a chemical fuel to the energy
available if the same mass were converted to energy through
nuclear decay (E=mc2).

Interactions of Energy and Materials properties of light and
lens
1. Energy waves may interact with materials leading to the
formation of heat or other forms of energy. These interactions,
which depend upon the nature of the material and the wavelength
of the radiation, can be used to create practical devices such as
electric heaters, solar cells, remote control units, and optical
communication devices.

Investigate the reflection, refraction, transmission, or
absorption of light waves by various materials.

Identify the different ways in which electrical conductors,
insulators, and semiconductors respond to an electric
potential. Discuss the differences in terms of the particulate
model of matter.

2. When radiation energy is absorbed or emitted by individual
atoms or molecules, the changes in energy involve the jump of an
electron from one distinct energy level to another. These energy
changes, which are characteristic of the atom or molecule, can be
used to identify the material.

Use flame tests to identify the various elements in a mixture.
Discuss how scientists use this technique to analyze unknown
materials or celestial bodies.

Describe things which are luminous such as fireflies, marine
organisms, and the Sun vs. things which are illuminated such
as the Moon, street signs, or bike reflectors.

Production/Consumption/Application of Energy

1. Demand for energy by society leads to continuous exploration in
order to expand supplies of fossil fuels (e.g., drilling deeper oil and
gas wells, drilling offshore). In addition, technology has been
developed to create alternate energy sources (e.g., solar collection,
ocean thermal energy conversion) and to increase the energy
efficiencies of commonly used machines and appliances.

Compare the advantages and disadvantage (including cost) of
different finite and renewable energy sources and identify
their applications.

Investigate the extent to which energy efficiency programs
involving a major societal use of energy (e.g., transportation,
farming, manufacturing, producing electricity) lead to
reduction in the amount of a natural resource consumed.

2. Advances in the scientific understanding of synthetic materials
have provided new devices (e.g., transistors, light emitting diodes,
optical switches, superconducting ceramics) used in electronic
equipment. This has revolutionized many aspects of life (e.g.,
communications, manufacturing, information processing, and
transportation).

Analyze the function of a modern electronic device (e.g.,
remote control unit, CD player) and compare its use with the
device which was previously used for the same function.
Describe the advantages offered by the replacement and
project possible extensions for other uses.

3. The increase in energy demand has environmental
consequences, and societal expectations for a sustainable
environment will require new, cleaner technologies for the
production of energy.

Working in groups, explore examples of the environmental
impact of energy sources used extensively in the past such as
peat, wood, or water and the societal and technological
changes which altered their use. Using this as background,
propose approaches to reduce the environmental impact of
current energy production technologies.
Solar System Models

1. The Solar System is a very small part of a constantly changing
Universe. Stars, including the Sun, appear to go through cycles that
are characterized by birth, development, and death. Existence of
gas and dust around nearby stars supports the theory that planetary
systems continue to evolve.

The following sample activities apply to this content
statement.

2 The stars in the Milky Way Galaxy are separated by vast
distances. Although it takes light from the Sun eight minutes to
reach the Earth, it takes the light from the next nearest star four
years to reach Earth. Light which reaches Earth from distant
galaxies is millions of years old and is actually a view of the past.

Research how light received from a star is used to determine
and quantify a star’s size, composition, mass, surface, and
temperature. Explain how scientists have used this
information to develop models of stellar evolution.

Investigate the indirect techniques used to measure large
distances between objects in the Solar System and galaxy,
and calculate the length of time it takes for light to travel
between objects in space.

3. The distance from the center of the nebula to points of
condensation determined the position of the planets in the Solar
System. The masses of the condensed protoplanets determined
which elements were retained, as well as their physical state.
Compare Earth’s chemical composition, size, and position in
the Solar System to those of other planets. Based on the
comparison, debate possibilities of the existence of life on
other planets.

4. The tilt of the Earth’s axis relative to its orbital plane does not
change as the Earth orbits the Sun during a year. Seasonal
variations of the apparent path of the Sun through the sky
determine how directly the Sun’s rays strike and warm different
areas of the Earth.

Construct Earth/Sun models to demonstrate how the amount
and distribution of energy that reaches Earth from the Sun
determine seasonal and global climates.

Interactions in the Solar System

1. Gravitation pulls planets toward the Sun balancing each planet’s
energy of motion. The gravitational pull of the Sun and the Moon
determine the times for high tides and the intensity of these tides
on Earth.

Apply the laws of gravitation to explain a variety of Solar
System phenomena (e.g., planets closer to the Sun must
move faster to maintain balance between the Sun’s
gravitational pull and the planets' energy of motion; tide
producing forces vary on different parts of the Earth; the
highest tides come about every two weeks at full and new
Moon).

2. Solar energy radiates through space and is distributed on Earth
by radiation, conduction, and convection. Energy transfer powers
atmospheric and oceanic circulation.
Measure and determine the range of frequencies of
electromagnetic radiation emitted from the Sun. On the basis
of these measurements, speculate how Earth maintains a
nearly constant average temperature.

Describe how various forms of energy are transferred by air
and ocean currents, and explain the role of this transfer of
energy in regulating the temperatures on Earth.

Technology and Application

1. Space exploration expands our knowledge of the Universe and
advances the technological sophistication of society.

Discuss ways society has benefited from space exploration
(e.g., production of new materials, development of
sophisticated computers, advances in satellite communication
technology). Research the economic implication of the space
program, and debate the pros and cons of future space
exploration.

Conduct a literature, film, or video search to describe and
discuss the history of the space program. Explain the
technologies involved in putting satellites, shuttles, and
people into space.

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