In a particle physics experiment, a detector is place in a magnetic field of 0.92 T.  A particle is found to produce a track of radius 0.5 m.  Other experiments have shown that the particle carries a charge of +1.6 ´ 10^-19 C and that its speed was 3.0 ´ 10⁷ m/s.  What is the mass of the particle?  How does it compare to the mass of an electron (9.11 ´ 10^-31 kg)?    

F = mv²/r and F = Bqv Þ mv²/r = Bqv (P)

Þ mv/r = Bq Þ m = Bqr/v (P)

m = 0.92 T ´ 1.6 ´ 10^-19 C ´ 0.5 m (P)

                   3.0 ´ 10⁷ m/s

m = 2.45 ´ 10^-27 kg (P)

This is 2700 times the mass of an electron (P).