One of Einstein's postulates in formulating the special theory of relativity was that the laws of physics are the same in reference frames that
A) accelerate.
B) move at constant velocity with respect to an inertial frame.
C) oscillate.
D) are stationary, but not in moving frames.
Question 2
Suppose you wanted to hold up an electron against the gravitational force by the attraction of a fixed proton some distance above it.
How far above the electron would the proton have to be? (k = 1/40 = 9.0 109 N m2/C2, e = 1.6 10-19 C, mproton = 1.67 10-27 kg, melectron = 9.11 10-31 kg)
A) 1.5 m
B) 2.3 m
C) 3.7 m
D) 4.6 m
E) 5.1 m