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Theory developed by Einstein connecting
measurements of space, time, and motion made by one observer to those made
by another observer in a different environment. |
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The general theory of relativity relates
observations made in strong gravitational fields to those found in weak
fields |
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Not studied in this course |
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The special theory of relativity relates
experimental results for two observers moving at high speed with respect to
one another |
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The speed of light, c = 300,000 km/s (3x108
m/s), is the same for all observers, regardless of their motion. |
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The laws of physics are the same for all
observers moving uniformly, that is at constant velocity. |
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Time dilation: t’= t/(1-v2/c2)
½ |
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for particle moving towards us with a velocity
v. Time appears to us slower.. |
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Allows muons created by cosmic rays high in the
atmosphere to get all the way to the ground before decaying |
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L = L’ x (1-v2/c2)½ |
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Length of very fast moving objects becomes
shorter in direction of motion. |
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If motion is perpendicular to the dimension
there is no change.. |
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http://www.walter-fendt.de/ph11e/timedilation.htm |
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http://www.walter-fendt.de/ph11e/timedilation.htm |
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Einstein’s rest energy equation |
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E0 = mc2 |
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Energy associated with a mass m, = m x square of
speed of light, C x C |
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E.g. m = 5 kg, E = 5 x3 x 108 x 3 x
108 |
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=45 x 1016 Joules |
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Gravitational force The attractive force
that acts between all pairs of objects. |
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Strong nuclear force It is the force that holds
neutrons and protons together in the nucleus. |
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Weak nuclear force It is responsible for beta
decay |
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Electromagnetic force The force that acts
between charged particles. Can be
attractive or repulsive. |
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Elementary particles The basic, indivisible
building blocks of the universe. The fundamental constituents from which
all matter, antimatter, and their interactions derive. They are believed to
be true "point" particles, devoid of internal structure or
measurable size. |
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Antiparticle A charge-reversed version of an
ordinary particle. A particle of the same mass (and spin) but of opposite
electric charge. |
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Some particles are emitted from the nucleus of
certain unstable atoms |
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These particles can be matter (electrons,
protons, …) or energy (X Rays and Gamma Rays) |
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Many Medical Tools Use this process |
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X Rays |
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PET (Uses Positrons and Emitted Gammas) |
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NMR (Nuclear Magnetic Resonance) |
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Radiation Therapy |
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The most advanced medical diagnostic imaging
technology available today for the early and accurate detection of cancer
and its recurrence. |
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also provides valuable information regarding
certain diseases of the heart (e.g., determination of tissue viability) and
brain (e.g., dementia, Parkinson's disease). |
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Formulas: (1- v2/c2 )1/2
used quite frequently |
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We have to square v and c and divide very big
numbers. |
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To make the math easy v is given in terms of c,
e.g. v = .9 c. This makes things
easy. |
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Because then v/c = .9c/c or .9 Since v2/c2
=(v/c)2 |
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v/c =.9
v2/c2 = .9 x .9 = .81 |
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and 1 - v2/c2 = 1-.81 =
.19 Then take sq.rt. of .19=.43 |
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Procedure take v/c, square it, subtract from 1
then take the square root of the result. |
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Power of 10 and number between 1 and 10 |
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3.3 x 106 |
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If you have 33 x 105 as your answer
you must convert 33 to 3.3 x 10
then add 1 to the power of 10, and you get 3.3 x 106 |
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Raymerry Home |
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Back to Physics |
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Notes
