試題詳解

59. How fast is needed for an O₂ ⁺ ion to move in a circular orbit of radius 5 m in a magnetic field of 0.5 Tesla? (1 u = 1.66 × 10^-27 kg)
(A) 3.8 × 10⁵ m/s
(B) 4.1 × 10⁵ m/s
(C) 5.2 × 10⁵ m/s
(D) 7.5 × 10⁶ m/s
(E) 8.9 × 10⁶ m/s