The force that is exerted by a magnet as it picks up iron nails ...

[wenmo]

The force that is exerted by a magnet as it picks up iron nails could be best described as
 
  A) the electric force exerted by electrons in the magnet, on electrons in the nails.
  B) the force of attraction between the nuclei of atoms in the magnet and the nuclei of atoms in the nails.
  C) the magnetic force exerted by electrons moving within the magnet, on electrons moving within the nails.
  D) the electric force exerted by ions in the magnet on electrons in the nails.
  E) the magnetic force exerted by ions moving within the magnet on electrons moving within the nails.

Question 2

In a mass spectrometer, a singly-charged particle (charge e) has a speed of 1.0  106 m/s and enters a uniform magnetic field of 0.20 T.
 
  The radius of the circular orbit of the particle is 0.020 m. What is the mass of this particle? (e = 1.60  10-19 C)
  A) 3.2  10-28 kg
  B) 6.4  10-28 kg
  C) 1.7  10-27 kg
  D) 4.5  10-27 kg
  E) 3.1  10-31 kg

[kusterl]

Answer to Question 1

C

Answer to Question 2

B

[wenmo]

Thanks for the timely response, appreciate it

[duy1981999]

Wow, this really help