An Exam Paper Contains the Following Equation for Rocket Propulsion

Multiple Choice

An exam paper contains the following equation for rocket propulsion:
)
The error in the equation is that,instead of (v + v_e) ,the velocity of the fuel relative to the ground should be

A) −v_e.
B) +v_e.
C) v − v_e.
D) v_e − v.
E) 2v_e.