एक सिरे पर बंद दो नलियाँ अपने मूल मोड (fundamental mode) में कंपन करते हुए प्रति सेकंड 2 विस्पंद (beats) उत्पन्न करती हैं। यदि उन्हीं नलियों के दोनों सिरों को खोल दिया जाए, तो उनके मूल मोड में कंपन करने पर प्रति सेकंड उत्पन्न होने वाले विस्पंदों की संख्या होगी:

Consider the following statements regarding waves: 1. If the particles of a medium move along the direction of propagation of the wave, the wave is called a longitudinal wave. 2. If the particles of a medium vibrate perpendicular to the direction of propagation of the wave, the wave is called a transverse wave. 3. Transverse waves involve changes in the shape/shear of the medium, whereas longitudinal waves involve changes in the density/volume of the medium. Which of the statements given above are correct?

At what speed should a source of sound move away from a stationary observer so that the observer perceives the apparent frequency to be half of the original frequency? (where v is the speed of sound)