An ion enters a mass spectrometer which has a 0.18 Tesla field ...

[mckennatimberlake]

An ion enters a mass spectrometer which has a 0.18 Tesla field perpendicular to an electric field of 1.6 kV/m and selects a velocity. The same magnetic field is then used to deflect the singly charged ion into a circular path of radius 12.5 cm.
 
  (a) What velocity was selected?
  (b) What was the ion mass?

Question 2

C. J. Davisson & L. H. Germer
 
  A) were first to produce X-ray-like diffraction patterns of electrons passing through thin metal foil (1927).
  B) were first to produce diffraction patterns of electrons in crystals (1927).
  C) predicted the positron from relativistic quantum mechanics (1928).
  D) set the limits on the probability of measurement accuracy (1927).
  E) discovered the positron using a cloud chamber (1932).

[lkanara2]

Answer to Question 1

(a) 8.9 km/s
(b) 4.1  10-25 kg

Answer to Question 2

B

[mckennatimberlake]

Wow, this really help

[jomama]

Excellent