Its main rotor

Has a center point A located L above point O

Is spinning at rate R relative to the body around the vertical axis

Has four blades of length $$

Has blade tips B$,$ C$,$ D$,$ and E located respectively to the right, left, front, and back of point A

Questions: For all questions below, assume that each rotor blade has a point mass m attached at its tip.

If the body of the helicopter is pitching forward at a constant rate

$$body$=[0$pitch$0]$

$(1)$ and has constant main$-$rotor rotational speed, what is the contribution to the moment at A on the main rotor from the acceleration of the mass at point D on the main rotor?