Does Electron Speed Impact Work and Position Uncertainty?

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The discussion focuses on two physics homework problems involving electron speed and position uncertainty. To determine the work required to increase an electron's speed, the formula for energy change in special relativity is essential. The confusion regarding position uncertainty arises from differing interpretations of the Heisenberg uncertainty principle, specifically whether to use h or h/2π in calculations. The participant expresses frustration with their current understanding and the quality of instruction received. Ultimately, clarification on the formulas resolves the issues presented.
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Heisenbergs..HELP PLEASE

Homework Statement



Does it take more work to increase an electron’s
speed from 0.5c to 0.9c, or from 0.9c to 0.95c?

i don't know where to start...


If an electron is traveling at 1 km/s, how
uncertain is its position?

I did the Px X=h/2pi and solved for X.. I got (1.2x10^-7) but the book gets 7.24x10^-7 I don't know what's with this


I'm extremely frustrated and pretty sick of this, my teachers quite useless as well... I'll just be honest, I'm going to Vet school but need physics to get into the program, so I just need to pass this course by the skin of my butt, so can someone please just give me the quick and dirty with how to do this because I'm really quite fed up with it ****bangs head off desk****
 
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Hi,
Stevo11 said:

Homework Statement



Does it take more work to increase an electron’s
speed from 0.5c to 0.9c, or from 0.9c to 0.95c?

i don't know where to start...
I assume that you have to use special relativity to solve this problem.
The amount of work to change the velocity of a particle is by definition the change in energy of the particle when it velocity changes from a velocity v_1 to a velocity v_2
I suggest you start with the formula for the energy which is
E=\sqrt{m^2c^4 + p^2c^2}
where p=\frac{m v}{\sqrt{1-v^2/c^2}}

If an electron is traveling at 1 km/s, how
uncertain is its position?

I did the Px X=h/2pi and solved for X.. I got (1.2x10^-7) but the book gets 7.24x10^-7 I don't know what's with this
It seems that they used h in the Heisenberg relation rather than h/2pi doesn't it?
 
They did use Heisenberg relation^ I asked my prof, and somehow my book has errors, but its all good now, thanks for the help :)
 
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