1. The problem statement, all variables and given/known data In this task, the basic criteria that enable a stable flight of a quadrocopter are examined. Our quadrocopter consists of four horizontal propellers which are interconnected crosswise in a massless manner in the so-called + -configuration (see Fig. 1, right). In the center of gravity of the quadrocopter, the control and batteries of mass mS = 500 g are attached. The propellers should all have the same moment of inertia IP = 6000gmm2, the same mass (including motor) mP = 90g and the same distance from the intersection point R = 100mm. However, they can rotate independently in different directions and at different speeds. We also assume that the buoyancy of each propeller is independent of its direction of rotation. It should also be directly proportional to the speed with the proportionality constant cA = 0.02kg m / s. a) Determine the rotational frequency of the quadrocopter ωQ as a function of the masses and the moments of inertia of the propeller IP. b) What relationship must be met between the rotational frequencies of the propellers so that the quadrocopter does not rotate about its center of gravity? Suppose that the amount of all rotational speeds is the same. (the question has been translated from german to english using google translate) 2. Relevant equations L=r x mv, T=r x F 3. The attempt at a solution For a) I am assuming that the frequency wQ is referring to the quadcopter itself and not the propellers? I don't even really know how to begin solving this problem because to me it seems that I need more information about the Situation to know what the roational requency is.. With b) I am also having trouble understanding what is meant..