Recent Changes

Time travel:
Special relativity:
of reference. It isIts called the
Will it work: (why or why not)
through time.
Heisenberg uncertainty:
of uncertainty.
Sources:
http://www.bbc.co.uk/dna/h2g2/A408638

Time travel:
Special relativity:
Einstein's theory of special relativity describes the motion of objects at near-light speed. It says that the speed of the light is constant whatever the relative speed of the observer, and the laws of physics are the same in all frames of reference. It is called the theory of special relativity because it has to do with relative motion.
Will it work: (why or why not)
According to special relativity, time slows as an object approaches the speed of light. So far it isn't known how to make an object go faster than light, because as it approaches the speed of light it's mass increases infinitely and therefore requires infinite force. Physicists believe that if it were possible for an object to travel faster than light, it would travel through time.
Heisenberg uncertainty:
WillThe Heisenberg uncertainty principle says that the position and velocity of a particle cannot be measured at the same time. By measuring the velocity of a particle using photons, the velocity of the particle is altered, and therefore makes it work: (why or why not)impossible to measure accurately. When measuring the velocity of large objects the difference is insignificant. But measuring a subatomic particle greatly affects it's velocity and there is a high percentage of uncertainty.
Sources:
http://www.bbc.co.uk/dna/h2g2/A408638
http://www.pbs.org/wgbh/nova/time/think.html

Source:
http://theory.uwinnipeg.ca/physics/work/node2.html#SECTION00510000000000000000
http://tutor4physics.com/casenowork.htm

Work:
Define:
Explain:Work is done by a force causing an object to have a displacement. Work equals the displacement times the force. If a force of 50 newtons causes an object to be displaced 10m, then the work done is 500 Joules.
Explain: A person pushes on a wall with a force of 200 newtons. The wall does not move. What is the total work done? work = displacement(0) * force(200). work = 0 joules
The total work done is 0 because although there is force applied to the wall, there is no displacement. 200 * 0 = 0
{http://tutor4physics.com/workwallpush.gif} ----
Equations:
work = displacement * force
Unit: Base or Derived:
joules
1 joule = 1 newton * 1 meter
Source:
http://theory.uwinnipeg.ca/physics/work/node2.html#SECTION00510000000000000000

Einstein:
{http://nobelprize.org/nobel_prizes/physics/laureates/1921/einstein.jpg} Albert Einstein
History:
Albert Einstein was born in Württemberg, Germany, on March 14, 1879.
Photoelectric effect:
Relativity:
Source:
http://nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-bio.html

Define: The period of a wave is the time it takes for the wave to repeat, or pass a certain point twice. When two consecutive peaks have passed a certain point, the wave has completed one cycle. If it takes 2 seconds for two consecutive peaks to pass a certain point, then the wave has a period of 2 seconds per cycle. Period equals 1 divided by the frequency.
Units: seconds minutes hours days years
Examples: A wave completes 3 cycles every second. What is the period of the wave? The frequency of the wave is 3 cycles per second. period = 1 / frequency(3) period = 1/3 seconds The period of the wave is 1/3 of a second.
Equations: p = period f = frequency p = 1/f
Unlike frequency, period is.......... period is the time it takes for the wave to complete one cycle. Frequency is how many cycles the wave completes in a certain amount of time. If a wave completes one cycle in 0.5 seconds, it's period is 0.5 seconds and it's frequency is 2 cycles per second.
Source: http://www.glenbrook.k12.il.us/gbssci/phys/Class/waves/u10l2b.html

Tension:
Define:
The tension force is a force directed through an object such as a cable that is being created by a force on the opposite end. If a force of 50 newtons is used to hold a rope that is suspending an object, the 50 newtons is transmitted through the rope to the object. Tension is measured in Newtons.
{http://www.maxedout.info/photos/Malaysia/where/42-3%20SuspensionBridge.jpg}
Examples:
A rope is used to suspend a 50kg object on Earth. Earth has an acceleration due to gravity of 9.8m/s/s.
What is the force of tension acting on the object from the rope?
Solve for the force needed to hold the rope in place. f = m(50)a(9.8) f = 490N
The force used to hold up the rope is transmitted through the rope and equal to the force of tension acting on the object.
The force of tension acting on the object from the rope is 490N.
Other topics:
Vector
Newton (Unit)
Sources
http://www.glenbrook.k12.il.us/gbssci/Phys/Class/newtlaws/u2l2b.html#tension
http://www.matter.org.uk/schools/SchoolsGlossary/tensile-force.html

Nuclear Energy:
{http://mesikammen.files.wordpress.com/2008/01/nuclear-bomb-badger350.jpg}
Define:
Nuclear energy is the form of energy created in a nuclear reaction. There are two kinds of nuclear reactions that create nuclear energy, nuclear fission and nuclear fussion. Nuclear fission is when nuclei are split to create energy. Nuclear fussion is when nuclei are combined to create energy. The energy created in nuclear reactors and by atomic bombs are created by fission. Fusion happens within stars.

Nuclear Energy:
Define:
Nuclear energy is the form of energy created in a nuclear reaction. There are two kinds of nuclear reactions that create nuclear energy, nuclear fission and nuclear fussion. Nuclear fission is when nuclei are split to create energy. Nuclear fussion is when nuclei are combined to create energy. The energy created in nuclear reactors and by atomic bombs are created by fission. Fusion happens within stars.
units: (base or derived)
Joules
Other topics
Scalar
Joule
Sources:
http://library.thinkquest.org/C005271F/physics.html
http://hyperphysics.phy-astr.gsu.edu/HBASE/NucEne/fusion.html
http://hyperphysics.phy-astr.gsu.edu/HBASE/nucene/fission.html