- #1

Elvis 123456789

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## Homework Statement

Suppose the electric field between the plates P and P' in the mass spectrometer in following figure is 1.89×104V/m and the magnetic field in both regions is 0.668 T.

If the source contains the three isotopes of krypton, 82Kr,84Kr, and 86Kr, and the ions are singly charged, find the distance between the two adjaicent lines formed by the three isotopes on the photographic plate. Assume the atomic masses of the isotopes (in atomic mass units) are equal to their mass numbers, 82, 84, and 86. (One atomic mass unit = 1u = 1.66×10−27kg.)

## Homework Equations

v = E/B

R = mv/qB

## The Attempt at a Solution

I found that the selected speed (v) is 2.83 * 10^4 m/s

I got 0.0360 m for the radius of 82Kr

0.0369 m for 84Kr

and 0.0378 m for 86Kr.

My problem is that I don't even understand what it is that they are asking for. What are these adjacent lines that they are talking about? and if there's three isotopes, shouldn't there be three lines?