A train traveling at a speed of 72 km / h emits short beeps every 5 seconds.

A train traveling at a speed of 72 km / h emits short beeps every 5 seconds. At the station, beeps are heard at intervals of 4.7 seconds. Find the speed of sound.

These tasks: Vp (train speed) = 72 km / h (in the SI system V = 20 m / s); tp (frequency of train beeps) = 5 s; tv (frequency of audibility of beeps at the station) = 4.7 s.

To determine the speed of sound, we use the equality: Vs * tp = S = Vp * tp + Vz * tv, whence Vz * (tp – tv) = Vp * tp and Vz = Vp * tp / (tp – tv).

Let’s make a calculation: Vz = 20 * 5 / (5 – 4.7) = 333.3 m / s.

Answer: The speed of sound, according to the calculation, is 333.3 m / s.