An a-particle has a charge of +2e and a mass of 6.64 × 10-27 kg. It is accelerated from rest through a potential difference that has a value of 1.20 × 106 V and then enters a uniform magnetic field whose magnitude is 2.20 T. The α-particle moves perpendicular to the magnetic field at all times. What is
(a) The speed of the a-particle,
(b) The magnitude of the magnetic force on it, and
(c) The radius of its circular path?