A Microphone in the Ocean Is Sensitive to the Sounds

question 61

Short Answer

A microphone in the ocean is sensitive to the sounds emitted by porpoises. To produce a usable signal, sound waves striking the microphone must have an intensity of 1.02 × 10−¹¹ W/m². If porpoises emit sounds with a power of 0.049 9 W, how far away can a porpoise be and still be heard? Disregard absorption of sound waves by the water.

---

Definitions:

Capsid

The protein shell that encases the genetic material of a virus.

Envelope

In biology, it commonly refers to the outer coating of a virus that protects its genetic material; in other contexts, it can mean a paper cover for letters.

Stanley Prusiner

A Nobel Prize-winning scientist known for his discovery of prions, a type of protein that can cause infectious diseases in the brain.

Biological Principle

Fundamental concepts that underpin the study of biology, such as the cell theory, gene theory, evolution, homeostasis, and ecology.