ON21 P23 Q3 Aircraft Forces and Sound | Oct/Nov 2021 | Cambridge A Level 9702 Physics

9702/23/O/N/21: (a) Define velocity. #9702w21p23 (b) A remote-controlled toy aircraft is flying horizontally in a wind. Fig. 3.1 shows the velocity vectors, to scale, of the wind and of the aircraft in still air. The velocity of the aircraft in still air is 42 m s–1 to the north. The velocity of the wind is 23 m s–1 in a direction of 54° east of south. Determine the magnitude of the resultant velocity of the aircraft. #ASvectorsP2 (c) The engine of the aircraft in (b) stops. The aircraft then glides towards the ground with a constant velocity at an angle θ to the horizontal, as illustrated in Fig. 3.2. The aircraft has a weight of 46 N and travels a distance of 280 m from point X to point Y. The change in gravitational potential energy of the aircraft for its movement from X to Y is 6100 J. Assume that there is now no wind. (i) Calculate angle θ. (ii) Calculate the magnitude of the force acting on the aircraft due to air resistance. #ASenergyP2 #ASfrictionP2 (d) The aircraft in (c) travels from X to Y in a time of 14 s. Fig. 3.3 shows that, as the aircraft travels from X to Y, it moves directly towards an observer who is standing on the ground. The aircraft emits sound as it travels from X to Y. The observer hears sound of frequency 450 Hz. The speed of the sound in the air is 340 m s–1. Calculate the frequency of the sound that is emitted by the aircraft. #ASdopplerP2 #Lv2 ON21 Paper Discussion Playlist    • 9702 ON21 Papers CAIE Physics   #WorkEnergyPower Playlist    • Ch5 Work Energy Power | CAIE 9702 AS Physics   #Waves Playlist:    • Ch7 Waves | CAIE 9702 AS Physics   Instagram Pocket Guide (  / etphysics  ) More Resources (https://9702-physics.blogspot.com/) Support us! (  / etphysics  ) Tuition/Tutoring inquiries: Email: [email protected] Whatsapp: https://wa.me/60126679171 #CambridgeALevelPhysics 9702_w21_qp23