Question Near the ground at the north magnetic pole, the Earth's magnetic field is directed downward vertically and has a strength of 0.57 G. An electron at the north pole is projected from the ground into this magnetic field with a velocity of 1.4 km/s vertically upward and 1.9 km/s horizontally. a) (12 points) Find the magnitude of the magnetic force acting on this electron. b) (9 points) Find the electron's acceleration (magnitude and direction). c) (6 points) Find the electron's period of rotation. d) (6 points) Find how long it will take this electron to reach a height of 10. m (assuming it does not collide with any air molecules). e) (3 points) The north poles of compass needles are attracted to the Earth's north pole because i) like poles attract. ii) the Earth's north pole is actually a south pole. iii) the Earth's poles have recently flipped but we have not officially changed their names. iv) compass needles are gravitationally attracted to iron deposited under the poles. v) compass needles carry small currents that align with the Earth's magnetic field. f) (3 points) When performing the calculations for this problem, we don't include gravitational forces because i) there is no gravity at the poles. ii) the gravitational force is negligibly small. iii) gravity only affects objects moving downward. iv) gravity only affects neutral objects. v) the magnetic field cancels out the gravity.