Special Relativity
and Kinematics
Gary Larsen Far Side
Question
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Which of the following are (is) finite
1) Maximum Speed an object can have
2) Maximum Kinetic Energy an object can have
3) Maximum Momentum an object can have
4) All of the above
5) None of the above
p/m0v
Test of SR momentum p=γm0v
For samples of electrons at different velocities
Measure v and p
Data fits the SR prediction
It does not fit the non relativistic prediction
Windsor Ontario – 580 megawatt natural gas-fired power plant.
Mass Out
(Gases,
Soot, Ash)
Mass In
(Fuel, Air)
Fossil Fuel
Power Plant
(Spherical
Approx.)
Energy Out
Heat,
Electricity
What is Mass_IN - Mass_Out?
Qualitatively?
Quantatively? Calculate
Assume 100% efficiency, no down time
580 megawatt
natural gas-fired power plant.
1 year ~πx107 seconds
1 watt = 1 Joule/second
580 megawatts = 6x108J/s x 3 x107 s/yr = 1.8 x1016 J/yr
E=mc2
m=E/c2
=1.8x1016J/(3x108m/s)2
=(1.8x1016/9x1016)kg
= 200g/yr
Mass Out
(Gases,
Soot, Ash)
Mass In
(Fuel, Air)
Fossil Fuel
Power Plant
(Spherical
Approx.)
MIN – MOUT = 200 g
200 g (Energy Equivalent)
So What is the Efficiency?
𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸
𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸+𝐻𝐻𝐻𝐻𝐻𝐻𝐻𝐻
𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸
(𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑖𝑖𝑖𝑖)𝐶𝐶2
= about 50%
= really really close to 0
Engineering view
Physics view