What is an ultrasonic sound?

Which has larger frequency – infrasonic sound or ultrasonic sound? (AS_2)

Write any two uses of ultrasonic sound.

A hospital uses an ultrasonic scanner to locate tumours in a tissue. What is the wavelength of sound in the tissue in which the speed of sound in 1.7kms^(-1) ? The operating frequency of the scanner is 4.2MHz.

What are the uses of infrasonic sound?

What are the uses of infrasonic sound?

A bat emitting an ultrasonic wave of frequecy 4.5 xx 10^4 Hz flies at a speed of 6ms^(-1) between two parallel walls. Find the two frequecies heard by the bat and the beat frequecy between the two. The speed of sound is 330ms^(-1)

A bat is flitting about in a cave, navigating via ultrasonic beeps. Assume that the sound emission frequency of the bat is 40kHz. During one fast swoop directly toward a flat wall surface, the bat is moving at 0.03 times the speed of sound in air. What frequency does the bat hear reflected off the wall?

What is meant by audible sound?