The ratio of electrostatic force F\(_E\) to gravitational force F\(_G\) between two protons each of charge e and mass m, at a distance d is
A
\(\frac{e}{4πε_oGm}\)
B
\(\frac{e^2}{Gm^2}\)
C
\(\frac{Gm^2}{4πε_oe^2}\)
D
\(\frac{e^2}{4πε_oGm^2}\)
Verified Correct Answer: D.
Physical Principles & Numerical Solution
Electrostatic force = F\(_E\) = \(\frac{e^2}{4\piε_od^2}\)
Gravitational force = F\(_G\) = \(\frac{Gm^2}{d^2}\)
\(\frac{F_E}{F_G}\) = \(\frac{\frac{e^2}{4\piε_od^2}}{\frac{Gm^2}{d^2}}\) = \(\frac{e^2}{4\piε_oGm^2}\)
NOTE: (d\(^2\)s canceled out)
Source: Myschool Past Questions Archive (Record #9033)