A beam of alpha particles is fired horizontally with a speed of 4.8 105 m/s into a region where there is a vertical magnetic field of magnitude 0.123 T. An alpha particle is the nucleus of a helium atom and as such, consists of two protons, two neutrons, and has a mass of 6.64 10-27 kg.

How long does it take for an alpha particle to move halfway through a complete circle?

The time taken for the alpha particle is 5.301x10⁻⁷s

Explanation:

The centripetal force is equal:

The magnetic force is equal:

Matching both expressions:

Where

m = 6.64x10⁻²⁷kg

v = 4.8x10⁵m/s

B = 0.123 T

q = 1.6x10⁻¹⁹C

The time taken for the alpha particle is:

found in the nucleus

has mass of one amu

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