(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A beam of protons with v=1.8x10^8 are deflected 90 degrees by a constant magnetic field. The trajectory of the beam has a circular arc with a radius of 4m.

I am asked to find the magnitude of the constant magnetic field.

2. Relevant equations

I know that r=mv/eB. When solving for B the equation is B=mv/er. Right?

m=1.67x10^{-27}

v=1.8x10^{8}

e=1.6x10^{-19}

r=4

3. The attempt at a solution

This gives me 7.515 for the magnitude of the magnetic field. The correct answer is 0.47T.

Did I start with the wrong equation?

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# Homework Help: Proton Beam therapy (magnetic field)

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