𝑆1 and 𝑆2 are two identical sound sources of frequency 656 Hz. The source 𝑆1 is located at 𝑂 and 𝑆2 moves anti-clockwise with a uniform speed 4√2 m s −1 on a circular path around 𝑂, as shown in the figure. There are three points 𝑃, 𝑄 and 𝑅 on this path such that 𝑃 and 𝑅 are diametrically opposite while 𝑄 is equidistant from them. A sound detector is placed at point 𝑃. The source 𝑆1 can move along direction 𝑂𝑃. [Given: The speed of sound in air is 324 m s −1 ] Consider both sources emitting sound. When 𝑆2 is at 𝑅 and 𝑆1 approaches the detector with a speed 4 m s −1 , the beat frequency measured by the detector is _______Hz.
𝑆1 and 𝑆2 are two identical sound sources of frequency 656 Hz. The source 𝑆1 is located at 𝑂 and 𝑆2 moves anti-clockwise with a uniform speed 4√2 m s −1 on a circular path around 𝑂, as shown in the figure. There are three points 𝑃, 𝑄 and 𝑅 on this path such that 𝑃 and 𝑅 are diametrically opposite while 𝑄 is equidistant from them. A sound detector is placed at point 𝑃. The source 𝑆1 can move along direction 𝑂𝑃. [Given: The speed of sound in air is 324 m s −1 ] Consider both sources emitting sound. When 𝑆2 is at 𝑅 and 𝑆1 approaches the detector with a speed 4 m s −1 , the beat frequency measured by the detector is _______Hz.