A helicopter of mass 3×10³ kg raises vertically with constant speed of 2 m/s, what resultant force acts on it?

Zero

3×10⁴ N downward

4.5 N upward

7.5×10³ N upward

When an object moves at constant speed, its acceleration is zero.

According to Newton’s Second Law:

F = ma → If a = 0, then F = 0