A train standing at the outer signal of a railway station blows a whistle of frequency 400 Hz still air. The train begins to move with a speed of 10 m/s towards the platform. What is the frequency of the sound for an observer standing on the platform? (sound velocity in air = 330 m/s)
A train standing at the outer signal of a railway station blows a whistle of frequency 400 Hz still air. The train begins to move with a speed of 10 m/s towards the platform. What is the frequency of the sound for an observer standing on the platform? (sound velocity in air = 330 m/s)
-
1 Answer
-
This is a short answer type question as classified in NCERT Exemplar
As the source is moving towards the observer hence apparent frequency observed is more than the natural frequency
Frequency of whistle
Speed of train = vt= 10m/s
Velocity of sound in air =v= 330m/s
Apparent frequency when source is moving vapp= (v/v-vt)v
= (
=
Similar Questions for you
The acceleration of wave is g/2. Its speed increases as it moves up. So answer is (2)
Distance between successive compression and rarefaction is λ/2
.
Both points B and G are moving up and are at same distance from equilibrium position at the instant.
Equation of component waves are
y = Asin (ωt – kx) and y = Asin (ωt + kx)
So speed of component wave is (ω/k).
Taking an Exam? Selecting a College?
Get authentic answers from experts, students and alumni that you won't find anywhere else
Sign Up on ShikshaOn Shiksha, get access to
- 65k Colleges
- 1.2k Exams
- 688k Reviews
- 1800k Answers