Physics Summary: Write your summary followed by your name. If you edit, write edited by and your name.

Scientific Measurement

Units:

  • Used for accurate measurements. * Very important for scientists to have standardized units. * Accuracy VS. PrecisionEx: Bull’s eye analogy===Metric System=== All scientists use Meters for the metric system. ===Metric Prefixes=== * Based on 10’s * Kilo 1x103 =1000 * Centi 1x10-2= .01 * Milli 1x10-3= .001===Dimensional Analysis=== Steps for Dimensional Analysis:# find given unit(s)# find desired unit(s)# plug in conversions# cross cancel and calculateEx: Convert 20km/15min to m/s
20km
1000m
1min
20000m
22.3m
15min
1km
60sec
900sec
s
Answer: 22.3m/s

Scientific Notation

Is a way to represent very small or very large numbers.
ex: a) 76 = 7.6 X 10
b) .008085= 8085 X 10^-6

Significant Digits

  • A type of rounding
  • All non-zero’s are significant digitsEx: 12.45 has four significant digits
  • Zeros are sometimes significant.Ex: 1200 has two significant digits
Ex: 12.00 has four significant digits
Summary By: Ashley Ann Yerena

Accuracy vs Precision

Accuracy is how close something is to the true value.
Precision is the consistency of multiple measurements.

Here is the common Bullseye Analogy

acc-prec.gif
acc-prec.gif
BY: Eddie Garcia

Edited by: Richard Fernandez

Authors: Ashley, Eddie, Richard

Classroom Library



Experimental Design

moz-screenshot-5.jpgScientific_method.jpg
- Experimental Design has no specific beginning. You can start on "develop theory" and continue through the design in a cycle.
- You must have a hypothesis before using the experimental design.
- To have a theory, your hypothesis cannot be impossible to test or wrong.
- The experimental design can help learn from your past hypothesis. If the one your working on is wrong, then start with another one. Through this process, you can learn what is wrong and what you can try in the future.
(Joseph Sosa)

Speed and Velocity

Speed

  • Speed has no direction but it does have magnitude.
  • Speed is also a scalar.===Velocity=== * Velocity on the other hand has speed and direction.
  • Velocity is a vector.
Gus and Edgar

Vectors

Vectors are arrows that represent magnitude and direction. Vector diagrams are used to describe the velocity of a moving object. If the vector arrow is to the right then it is positive. If the arrow points to the left then it is negative. Vectors should have a key since each dash equals a certain unit.
U1L2c2.gifKEY 1 CAR= 10M
This diagram is showing 50 M to the positive side.
By: Cindy and Vanessa

Acceleration

Definition: The rate at which an object's velocity changes with time.
external image U1L1e5.gif external image acceln.gif
The average acceleration of any object can be calculated by using the following equation:
external image U1L1e2.gif
Acceleration is usually expressed in units of velocity/time, for example: m/s/s, mi/h/s, km/h/s, m/s(squared). Acceleration is a vector qauntity, meaning it is associated with a direction. The direction of the acceleration vector is determined by whether the object is speeding up or slowing down and whether an object is moving in the positive or negative direction.
Anim'n of a car w/a and v vectors drawn
Anim'n of a car w/a and v vectors drawn

By: Jaclyn Lopez



Gravity

Gravity is an invisible pulling force between 2 objects .The amount of gravity depends on how big or small your object is.Gravity is required to change the direction or speed of something that is moving.

Formula- Gravitational force = (G * m1 * m2) / (d2)
external image r?t=a&d=us&s=a&c=p&ti=1&ai=30751&l=dir&o=0&sv=0a300511&ip=4b327311&u=http%3A%2F%2Fwww.dmturner.org%2FTeacher%2FPictures%2Fchair.gif(Diana Perez)


Projectile Motion

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Projectile motion is the course in which an object takes due to the forces surrounding it.

pm2.gif
In this picture you can see how the objects desired destination was
not fulfilled due to the force of gravity that pushed DOWN upon the object.
The Concept or Projectile motion is experienced in everyday life. You see
it occurring when you throw a football or launch a rocket.

Browns
tom brady

WindowClingTomBradyStanding.jpg
BrownsBrownsBrownsBrownsBrownsBrownsBrowns
BrownsBrownsBrownsBrowns
Alyssa Fisher



Displacement


  • Displacement is a vector and it is a change in position, it is NOT always equal to the distance traveled.

Formula:
pix22.jpg
Displacement = Final Position – Initial Position


displacement.png

BY: Armando Cortez



Newton's First Law of Motion


  • Newton's first law of motion states that an object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by unbalanced forces.
by: Christina Giordano



Newton's Second Law of Motion


  • Newton's Second Law of Motion states that acceleration is proportional to the force applied but inversely proportional to mass.
  • Acceleration describes how quickly motion changes
  • Acceleration= change in velocity/time interval
  • Net Force=the combination of forces acting on an object & Force causes acceleration so....
    • Acceleration ~ Net Force "~" means "IS directly proportional to"
    • Acceleration also depends on the mass being pushed. So acceleration is inversely proportional to the mass: Acceleration~1/Mass
    • Inversely Proportional means that the two values change in opposite directions
  • When you put all of this together you get, Acceleration~Net Force/Mass which is Newton's Second Law of Motion, =)
by: Claudia Corona



Thermal Equilibruim


external image calibrate-zero.jpg
This image illustrates how the thermometer is measuring the temperature of both the water and ice. Over this period the ice will melt and once the ice melts it will reach a constent temperature with the water. It will either increase or decrease.
  • Thermal Equilibrium is when to ocjects approach the same temperatureand will continue in having a constent temperature.



    By: Norma Cruz
    ----

Newton's Third Law of Motion


  • Newton's Third Law of Motion states that for every action force there is an equal(in size) and opposite(in direction) reaction force
  • Force ALWAYS comes in pairs-known as "action-reaction force pairs"
    • In order to identify the pairs you must know the two interactive objects and make two statements describing who is pushing who and in what direction.
  • EXAMPLE:
    • Interaction between a baseball bat and a baseball
    • 23424657.jpg
      23424657.jpg
      • The baseball forces the bat to the left
      • The bat forces the baseball to the right
      • TOGETHER, these two forces exerted upon 2 different objects, form the action-reaction force pair, which happens to be Newton's 3rd Law of Motion, =D
by: Claudia Corona

Momentum

Definition: Momentum is equal to the direction and speed of an object multiplied by its mass. The formula is p=mv..(the bold letters are vectors)Momentum is labeled with the units "kg*m/s and a direction, which is a vector quantity.

Example Problems:
1. What is the momentum of a 100kg man running northwest at 10m/s?
a. 100kg*10m/s=1000kg*m/s northwest

2. Who has more momentum in the following situations? Christina, with a mass of 50kg, running east at 5m/s. Bryan, with a mass of 60kg is running west at 4m/s/
a. Christina's momentum=50kg*5m/s=250kg*m/s
b. Bryans's momentum=60kg*4m/s=240kg*m/s
c. Christina has more momentum.
Momentum_4.gif
Momentum_4.gif

by: Karen Rayas


Work

Definition - the amount of energy transfered by a force

Types of Work

There are 2 types of work which are Kinetic and Potential Energy. Together they both make up Mechanical energy.
Kinetic energy ; Is the energy in motion such as rotational, vibrational, or translational motion.
Potential energy : Is the stored energy on its posistion such as gravational or elastic energy.
Mechanical energy : Is when work is done by potential and kinetic energy.

Formulas:

The formula for Kinetic energy is; KE= .5*m*v^2

The formula for
Potential energy is; PE=m*g*h

The formula for Mechanical energy is; ME= PE + KE

external image yoyoenergy.gif


Examples:

1. A 1,000 ton roller coaster reaches its maximum height of 200 ft what's its potential energy?

2. If the roller coaster is traveling at 100 m/s and reaches a height of 0 what's its kinetic energy?

3.What's the total Mechanical energy?


Answers:

1. 2,000,000 joules
2. 5,000,000 joules
3. 7,000,000 joules


--Leo
--Edited by Danny Guerra P.2



Force

Definition- a push or pull (between two interaction objects)
Force is measured in Newtons
Force is a vector quantity
The effect of force depends on magnitude and direction

Formula

F=MA

2 Categories

Contact Forces-two interactingobjects that are perceived to be physically contacting each other.
Ex. frictional force,tensional force,air resistance
Actions-at-a Distance Forces-forces which result even when the two interacting objects are not in physical contact with one another.
Ex. gravitational pull,magnetic force
by:yesica lopez




Impulse

Definition- The average value of a force applied over a period of time. (Average force applied divided by the time it took to apply the force). The product of force and the time the force acts on it; impulse causes a change in momentum which is basically the average value of a force applied over a period of time.
moz-screenshot-24.jpgmoz-screenshot-25.jpg
imp1.gif
This is the Formula used to find impulse and change in momentum.

By: Jose Almeda

HEAT==
Encyclopedic entryexternal image HeatWave1.jpg


=

RADIATION

Definition: Radiation, as used in physics, is energy in the form of waves or moving subatomic particles.

Types of Radiation:
  • Electromagnetic radiation: (Energy in the form of electromagnetic waves or photons.)
  • Particle radiation: (Energy in the form of moving subatomic particles.)
    • Alpha radiation, composed of the nuclei of helium-4 atoms
    • Beta radiation, consisting of energetic electrons or positrons
    • Neutron radiation, consisting of neutrons
<img src="http://www.ux1.eiu.edu/~cxtdm/met/radiation_pres.jpg">
by: Siray Rodgers

Irma Cruz





=

The First Law of Thermodynamics

The first law of thermodynamics states:The increase in the internal energy of a system is equal to the amount of energy added by heating the system, minus the amount lost as a result of the work done by the system on its surroundings.

The equation for this law is the change in U(internal energy=Q(heat added)-W(work done) U=Q-W
This is the conservation of energy which means that energy is never created or destroyed, only transfered.

Example:(PISTON ENGINE)
The energy/heat in this engine is not being destroyed but transfered. The darkest red symbolizes the most heat as it moves through the piston chambers the red turns to blue showing how energy disapates/transfers in to sound energy/heat energy/ and the friction of the moving pistons. As well as heat being lost to the surrounding environment.

Image:Triple expansion engine animation.gif
Image:Triple expansion engine animation.gif


Second Law of Thermodynamics

Thermodynamics is a branch of physics which deals with the energy and work of a system.The second law of thermodynamics is an expression of the universal law of increasing entropy stating that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium. In simple terms, the second law is an expression of the fact that over time, ignoring the effects of self-gravity, differences in temperature, pressure, and density tend to even out in a physical system that is isolated from the outside world. Entropy is a measure of how far along this evening-out process has progressed.
There are two processes happened on thermodynamics; reversible and irreversible process. An example of reversible process is ideally forcing a flow through a constricted pipe. As the flow moves through the constriction, the pressure, temperature and velocity change, but these variables return to their original values downstream of the constriction. While an example of irreversible process is when a hot object is combined with a cold object. Eventually, they both achieve the same equilibrium temperature. If we then separate the objects they remain at the equilibrium temperature and do not naturally return to their original temperatures.
thermo1.gif

Gerstine

Convection


Convection is the movement of heat and matter from particle to particle.

Conduction is the transfer of thermal energy through matter.

Radiation is the energy in form of waves.

-Edited by Danny Guerra


CoNdUcTiOn: BY IRMA
Heat conduction or thermal conduction is the transfer of thermal energy through matter, from a region of higher temperature to a region of lower temperature. In other words is the distribution of heat energy from atom to atom within a substance.
conduction.jpg heat_conduction.jpg

The picture on the left shows the heat of the candle This other picture (the one on right) shows the flow of the
being transfer to the stick and the arrow shows the heat and it shows that the particles are transferring from a
direction of the transferred heat. region of high temperature to a region of low temperature.

EXAMPLES:
  • For example, a spoon in a cup of hot soup becomes warmer because the heat from the soup is conducted along the spoon.
  • Another example is when you add cold milk to a hot coffee the milk becomes warmer because the heat from the coffee is conducted to the milk.
  • Thirdly, when two peoples shake hands the heat from one of the hands depending on the higher temperature is conducted to the other hand the one with the lower temperature.


Raymundo Cruz
Net Forces: The total amount of force applied to an object.
Image:Parallel net force.jpg
Image:Parallel net force.jpg

  • When force A and force B act on an object in the same direction (parallel vectors), the net force (C) is equal to A + B, in the direction that both A and B point.

Image:Antiparallel net force.jpg
Image:Antiparallel net force.jpg

  • When force A and force B act on an object in opposite directions (180 degrees between then - anti-parallel vectors), the net force (C) is equal to |A - B|, in the direction of whichever one has greater absolute value ("greater magnitude").

Image:Non-parallel net force.jpg
Image:Non-parallel net force.jpg

  • When the angle between them (the forces) is anything else, then the individual components must be added up using sine and cosine.
More than one force can act on an object at once. For example, two people could push on a book at the same time. One person could push toward the left and the other could push toward the right. In this case the two forces would act against each other. If the force toward the left was greater than the force toward the right, then the prevailing force would be toward the left. The strength of this prevailing force would be the difference between the strengths of the two separate forces. In this prevailing force is called the net force. Basically, the word net means total.


lizbeth

Law of Conservation of Momentum

Definition: "For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. That is, the momentum lost by object 1 is equal to the momentum gained by object 2."¹

The total momentum between the two objects colliding in conserved, or has a constant or unchanging value. The external force acting between the two objects have the same magnitude and opposite direction. This is because the center of mass of a system of objects will have the same velocity unless acting on by an external force (Newton's First Law of Motion).
This animation shows how the objects have the same magnitute, yet opposite directions.


momentum.gif


Another example that shows the law of conservation of momentum would be Newton's Cradle (pictured below)

newtons_cradle.jpg
Newton's Cradle


1.Physics Classroom Tutorial

-Debbie :]


external image inelasticcollision.JPGexternal image inelasticcollision.JPG
Projectile Motion By Yesenia Saldana

A projectile is an object in which only gravity act upon it. There are diiferent types of projectiles. An object can be dropped from its rest point. An object thrown vertically upward. An object thrown vertically at an angle. A projectile is an object that once thrown, dropped or projected it continues in its own motion and and the force acted upon it is the downward of gravity.


u3l2a2.gif





Gravity-free environment by: Omar Ocaranza
Anim'n of Monkey and Zookeeper Demonstration
Anim'n of Monkey and Zookeeper Demonstration

Since there is gravity on Earth, if the monkey lets go of the tree he will fall to the ground. If the banana is launched straight at the monkey and the monkey lets go of the tree then he wont catch the banana. If there weren't any gravity, as shown in this picture, the monkey would stay in it's place and the banana would go straight to the monkey.









Elastic And Inelastic collision By: Reyna Ortiz
First of all a collision is when two objects come together or collide and energy is converted into momentum or kinectic energy
Defintions:
Elastic Collision----> Its a collision in where there is no loss of kinectic energy!
Inelastic collision--> is when a collision occurs but some of the kinectic energy is transformed into another type of energy!

When an inelastic collision occurs the objects collide but they do not bounce away from eachother! They dont bounce away from eachother due to the fact that the momentum is conserved because the momentum of the objects is the same before and after the collisoin in this case the crash! Like i said some of the kinectic energy is converted , in this case the kinectic energy is converted to sound and heat.
external image inelasticcollision.JPG

When a elastic collision occurs the objects that collide do bounce away from eachother! In this type of collision the momentum and the kinectic energy are conserved. In the following example the momentum and kinectic energy are pass from object to object!
external image boing.gif

Internal Energy

  • the energy of a substance due to both the random motion of it's particle

  • the total amount of kinetic and potential energy in a substance external image intex.gif


by:Jerae Ortiz

POTENTIAL ENERGY


Defenition: The energy of position. Something potential to change the states of objects in the systems when the energy is released.
,PE = mgh
,PE = mgh

,PE = mgh

  • PE = Potential Energy
  • M = Mass
  • G = Gravity
  • H = Height

wrecking.gif
wrecking.gif
This Wrecking ball as it's hanging in the air has alot of potential energy beacuse of it's position, it has the potential to cause alot of damage to something, When the wrecking ball is let go it releases all the energy and become kinetic energy.

Heat Capacity

Heat Capacity is the amount of energy required to raise the tepmurature of a sibstance by on degree. The more solid a substance the higher heat capactiy it has. For exapmle: Water has a higher heat capacity thaan air because it will typically take longer for it to heat up when left near a heat source. We saw this in the Heat capacity, Co2, and Greenhouse Effect Lab. The air & the Co2 raised in tempurature when near a light, while the water's tempuratre stayed tha same.
(by: Clem Hernandez)