A source of sound is attached to a rope and then swung at a constant speed in a horizontal circle, as illustrated in Fig. 5.1. [Figure 5.1] The source moves with a speed of 12.0ms⁻¹ and emits sound of frequency 951 Hz. The speed of the sound in the air is 330ms⁻¹. An observer, standing a very long distance away from the source, hears the sound.

1. (a)Calculate the minimum frequency, to three significant figures, of the sound heard by the observer. minimum frequency = ..................................................... Hz[2]
2. (b)The circular path of the source has a radius of 2.4 m. Determine the shortest time interval between the observer hearing sound of minimum frequency and the observer hearing sound of maximum frequency. time interval = ..................................................... s[2]

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