Page:Aerial Flight - Volume 2 - Aerodonetics - Frederick Lanchester - 1908.djvu/428

App. VIIIb. § 107 and suppose that each element of the area of the boomerang experiences a reaction proportional to the square of its velocity, we shall have the centre of pressure displaced as

Fig. 191.

represented diagrammatically in Fig. 193 (a). In this figure it is evident that the motion of the boomerang viewed from above being counter-clock, the centre of pressure is displaced to the

Fig. 192. Fig. 193.

right, and the resulting torque, from the point of view of the thrower, is counter-clock. Consequently the angular momentum imparted to the boomerang about the axis of flight will also be counter-clock, and owing to the rotation it will be angular momentum of aspect; it is therefore the upper face of the