What is the frequency of infra- sound and ultrasound?

What is the intensity of painful sound?

A train standing at the outer signal of a railway station blows a whistle of frequency 400 Hz in still air .The train begins to move with a speed of 10ms^(-1) towards the platform. What is the frequency of the sound for an observer standing on the platform?(sound velocity in air = (330ms^(-1)) )

What are ultrasounds?

A SONAR system fixed in a submarine operates at a frequency 40.0 kHz. An enemy submarine moves towards the SONAR with a speed of 360 km h^-1 . What is the frequency of sound reflected by the submarine ?Take the speed of sound in water to be 1450m s^-1 .

A SONAR system fixed in a submarine operates at a frequency 40.0 kHz. An enemy submarine moves towards the SONAR with a speed of 360 kmh^(-1) .What is the frequency of sound reflected by the submarine? Take the speed of sound in water to be 1450 ms^(-1) .

What is the nature of the sound waves?

What is the velocity of sound on moon ?

What is the cause for production of sound ?