View Full Version : Confused to the max! Re-aranging equations.
Okay so today i sat a AS level physics paper and after finishing the exam i looked threw the equation booklet and decided to do some manipulation and i came up with this and was wondering what you guys think of it. Im confused!! :)
E=hc/λ AND λ=h/mv
subbing in gives E=hcmv/h which is E=cmv
conservation of energy...
cmv=1/2mv^2
2c=v
how can velocity = 2*speed of light?
Thoughts?
Okay so today i sat a AS level physics paper and after finishing the exam i looked threw the equation booklet and decided to do some manipulation and i came up with this and was wondering what you guys think of it. Im confused!! :)
E=hc/λ AND λ=h/mv
subbing in gives E=hcmv/h which is E=cmv
conservation of energy...
cmv=1/2mv^2
2c=v
how can velocity = 2*speed of light?
Thoughts?
Just because something has the same name or the same symbol, does not mean they are representing the SAME thing.
E=hc/\lambda is the energy per photon with that particular wavelength, whereas \lambda=h/mv is the deBroglie wavelength for a non-relativistic particle with mass m at velocity v!
You can't simply substitute apples into oranges. If you do that, you get ridiculous answer like what you got.
Zz.
vBulletin® v3.8.7, Copyright ©2000-2012, vBulletin Solutions, Inc.