Problem 11-71 Grav & Elec Potential - B

A particular proton in space is subjected to two fields: a gravitational field (\(1.30 \times 10^5\; N/kg\)  toward planet \(X\)), and an electric field (\(2.47 \times 10^{-4} \; N/C\) away from planet \(X\)).

(a) If the proton is released from rest, in which direction will it move?
(b) After moving \(1.50 \;m\), what will be its speed? Use energy methods and assume uniform fields.

Accumulated Solution

Diagram B of proton subjected to two fields.


Which are the correct expressions for the magnitudes of the two forces, that is, the Electric force \(F_E\) and the gravitational force \(F_g\) ?

(A)   \(F_E = mg   \quad  F_g = qE\)

(B)   \(F_E = qE   \quad  F_g =  mg\)

(C)   \(F_E = qg  \quad   F_g = mE\)