a resume helicopter has a total mass of 9000 kg. when the helicopter is hovering at constant altitude, what is the force produced by the rotating blades? which direction is this force? when taking off, the helicopter accelerates upwards at .6 m/s^2. in this situation, what is the force produced by the rotating blades? which direction is this force? when landing, the helicopter moves downward at a constant speed of .16 m/s. in this situation, what is the force produced by the rotating blades? which direction is this force? after landing and shutting down, the helicopter sits motionless on the landing pad. what is the force produced by the ground on the helicopter? what direction is this force