Ultrasound is a medical technique that transmits sound waves through soft tissue in the human body. Ultrasound waves can break kidney stones into tiny fragments, making it easier for them to be excreted without pain. The shattering of kidney stones with specific frequencies of sound waves is an application of which wave phenomenon?

(1) the Doppler effect
(2) reflection
(3) refraction
(4) resonance

option (4)

Explanation:

It is due to the resonance.

When the natural frequency of the stones matches with the frequency of ultrasound waves, the resonance occurs.

So, as the resonance occurs, the stones break into small pieces which can be removed easily by the medical equipment.

Thus, option (4) is correct.

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

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