Physics

Problem

AP Physics Free Response Practice - Magnetism and Electromagnetism ## SECTION A - Magnetism ![](https://storage.googleapis.com/diraq-contents/question-bank/question-images/13e60ebe737e/2025_11_20_a06764ffad9cea2721f0g-16.jpg) 1975B6. In a mass spectrometer, singly charged

{ }^{16} \mathrm{O}

ions are first accelerated electrostatically through a voltage V to a speed

\mathrm{v}_{\mathrm{O}}

. They then enter a region of uniform magnetic field B directed out of the plane of the paper. a. The

{ }^{16} \mathrm{O}

ions are replaced with singly charged

{ }^{32} \mathrm{~S}

ions of twice the mass and the same charge. What will be their speed in terms of

\mathrm{v}_{\mathrm{o}}

for the same accelerating voltage? b. When

{ }^{32} \mathrm{~S}

is substituted for

{ }^{16} \mathrm{O}

in part (a), determine by what factor the radius of curvature of the ions' path in the magnetic field changes.

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