A small particle of charge |q |= 1.610^-19C and mass m = 1.67 10^-27kg is accelerated over a potential difference of 220 V before it enters a region of uniform magnetic field that points into the page (see the figure). The particle is observed to travel in the semicircular path shown, with radius R = 5.0 cm.

a) How fast is the particle moving when it enters the uniform field? b) What is the magnitude the magnetic field? c) What is the sign of the charge of the particle?Justifyyour answer.

Express your answer with the appropriate units.

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