Solving Mass Spectrometer Homework Problem with 90SR+ Isotope

AI Thread Summary
The discussion revolves around solving a mass spectrometer homework problem involving the isotope 90SR+. The user correctly calculated the speed of the isotope at 25.72*10^4 m/s but struggled with finding the required voltage difference for acceleration. They initially arrived at a voltage of 30866.73 V, significantly higher than the professor's answer of approximately 308 V. Upon reviewing their calculations while typing out the problem, the user identified an error that led to the discrepancy. The discussion highlights the importance of careful problem-solving and verification in physics homework.
Millimole
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Homework Statement



I'm having problem with a couple parts of this problem. I know how to work it (I think), but I'm consistently off by a couple orders of magnitude off the answer provided by the professor.

I've already found that the isotope 90SR+ needs to be given a speed of 25.72*10^4 m/s. This much I know is correct. From there I am asked to find the voltage difference required to accelerate the isotope to this speed.


Homework Equations



U=qV
U=.5mv^2

q (elementary charge): 1.602*10^-19 C
m (mass of isotope): 1.495*10^-25 Kg

The Attempt at a Solution



Set the two equations equal to one another. Find the kinetic energy of the isotope traveling at the needed speed. Divide this value by q (charge of a +1 ion). I get the answer 30866.73 V. Professor gets roughly 308 volts. Granted, his answer makes more sense than mine, but I cannot for the life of me find the fault in my work. Note: I calculated the mass of the isotope, but since it yielded the correct answer in a previous question, I assume it is correct. Someone tell me how the hell I'm off by two orders of magnitude?
 
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False alarm everybody. Typing out the problem helped me catch the error. Cheers!
 
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