There is a great website called, "The Physics Classroom", where you can experience even more of the physics we have looked at this year. You will find it at the link below.

http://www.physicsclassroom.com/reviews/




Here is an MCAS review that Mrs. Sullivan put together a few years ago.



This is what it looks like without all the pictures.
Physics MCAS Study Guide
Motion and Forces

Velocity is the rate of change of position (distance traveled ÷ time) (m/s, km/h)

external image 0clip_image002.pngAcceleration is the rate of change of speed (change in speed ÷ time) (m/s2)

The slope of a d-t graph is velocity.
The slope of a v-t graph is acceleration.

Vectors are quantities that require a direction to be fully understood.

Vectors add using the head-to-tail method.

A force is a push or a pull measured in Newtons.
Force is a vector quantity.
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A free-body diagram is a vector diagram of all the forces acting on an object.

If all the forces on an object add to zero, the object is in equilibrium and will not change its motion (will stay at rest, or stay moving at a constant speed in a straight line).

If all the forces on an object add to a non-zero value, the object will accelerate, according to F = ma.

Friction is a force that opposes motion. Static friction needs to be overcome to start an object moving, sliding friction needs to be overcome to keep an object moving at constant velocity.

Every force has an equal and opposite force. Example: The force of the moon on the earth is equal to the force of the earth on the moon.
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An inward force is required to keep something in circular motion.





The Law of Universal Gravitation follows the inverse square law, which means the force decreases rapidly as object get farther apart.

Momentum is the product of mass times velocity. Unit- kg m/s

The Conservation of Momentum says that the total momentum of a system will stay constant. So the momentum before a collision or explosion will be the same as the momentum after.


Energy
The units of energy is JOULES

Work is the transfer of energy. You can find work by force x distance, or by finding how much potential energy increased, or kinetic energy increased.

Power is the rate at which work is done, so it is work ÷ time. If the same work is done faster, it requires more power. The unit of Power is Watts

Gravitational Potential Energy is the energy an object has due to its position. The higher up it is the more potential energy it has. To calculate PE: multiply mass times g times height.

Kinetic Energy is the energy of motion. The faster an object is moving the higher its kinetic energy. KE = ½ mv2.

Energy can change from PE to KE to PE, etc. For example, on a rollercoaster, you have maximum potential energy at the top of the hills (highest height) and maximum kinetic energy at the bottom of the hills (highest speed).

Heat

Heat is the flow of thermal energy, which always flows from hot to cold.

Temperature is a measure of the average kinetic energy of molecules.

As a substance heats up (absorbs thermal energy) its molecules move faster and get farther apart. Remember, molecules moving faster also means kinetic energy increases.

Methods of heat transfer:
Conduction- objects must be touching- heat is transferred by the collision of molecules. Example: a iron poker in a fire becomes hot at the fire end and the heat travels down the poker to your hand through collisions of molecules. Conduction can happen in solids, liquids, and gases.
Good conductors (like metals) have loose electrons and can transfer energy through collisions easier.
A poor conductor is a good insulator.

Convection- “heat rises”. Air at the ceiling is warmer than air at your feet.
Convection happens only in liquids and gases (fluids). If you put your hand around a candle, you will feel the heat high above, but not until real close on the sides.

Radiation-heat that is transferred by electromagnetic radiation (infrared rays). For example, heat from the sun, or heat that you can feel in front of a fire.

The amount of heat transferred is given by Q = mc∆T. Q is the amount of heat that is transferred, m is mass, c is specific heat, and ∆T is change in temperature.

Phase changes occur when substances are at their melting/freezing or boiling/condensing temperatures and energy is absorbed or released. No temperature change occurs during a phase change.

Evaporation is a cooling process (as water evaporates off you skin you are cooled)
Condensation is a warming process (you can be very badly burned when steam condenses on your skin).

WAVES
Waves transfer energy.
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Period (T)- time to complete on cycle. Often measured in seconds.

Frequency (f)- # cycles completed in a unit of time. Unit- Hz (1/seconds)
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CSullivan:Users:sullivanc:Desktop:2008551448_sine_wave.png
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These two quantities are inverses of each other :
T = 1/f
f = 1/T


Transverse wave- pictured above.
Longitudinal wave-pictured at right.
Mechanical waves- waves that need a medium, like sound or water waves.

Mechanical waves cannot travel through a vacuum.
The speed of a mechanical wave is determined by the properties of the medium.

Sound travels fastest in solids, then liquids….slowest in gases.
Sound waves are longitudinal.

Electromagnetic waves- waves emitted by accelerating electric charges. Energy is partly electric and partly magnetic. Includes radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.

Electromagnetic waves can travel through a vacuum.
They travel at 3 x 108 m/s.

external image 0clip_image014.pngEnergy increases as frequency increases, so gamma rays have the highest energy, anand radio waves the lowest.

Electromagnetic waves are











external image 0clip_image016.pngAngle of Incidence = Angle of Reflection








Refraction-happens when a wave bends due to the difference in wave speed in different materials. Wave bends toward the normal if wave travels into a more dense medium.

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Electricity and Magnetism

Two charges, + and -

If something has a – charge, it has more electrons than protons, so it has gained electrons.

If something has a + charge, it has more protons than electrons, so it has lost electrons. NOTE: substances cannot gain or lose protons.

Like charges repel, opposite charges attract. The force that causes this is directly proportional to the two charges, and indirectly proportional to the square of the distance. This means that the attractive or repulsive force between charged particles drops off very quickly.

Voltage = current x resistance
V = IR

Current is the flow of charge - Units of current – amps (A)
Units of resistance – ohms (Ω)
Units of voltage – volts (V)

Power is current x voltage
P = IV

To find Total Resistance in a series circuit add the resistors. This is why as you add lightbulbs in a series circuit they dim (total resistance increases).

To find the Total Resistance in a parallel circuit find the inverse of the sum of the inverses of the resistors. This is why as you add lightbulbs in a parallel circuit they actually get brighter (total resistance decreases).

In a series circuit, if one lightbulb goes out, all others will go out- circuit is broken.

In a parallel circuit, if one lightbulb goes out, the others can remain lit.