The following are the capital letters corresponding to do, re, mi, fa, sol, la, and si.

The following are the frequencies of each note in the key of C major.

C:261.6256. Since C represents do, the frequency of do is 261.6256 Hz.

D:293.6648. Since D represents re, the frequency of re is 293.6648 Hz.

E:329.6276. Since E represents mi, the frequency of mi is 329.6276 Hz.

F:349.2282. Since F represents fa, the frequency of fa is 349.2282 Hz.

G:391.9954. Since G represents sol, the frequency of sol is 391.9954 Hz.

A:440. Since A represents la, the frequency of la is 440 Hz.

B:493.8833. Since B represents si, the frequency of si is 493.8833 Hz.

Extended information:

Acoustics refers to anything related to hearing. But as commonly used, one refers to the branch of physics about the properties, production and propagation of sound; the other refers to the quality of a building suitable for listening to speech and music clearly.

Sound is produced by the vibration of an object (such as a musical instrument) and travels through the air to the eardrum, which also vibrates at the same rate. The pitch of sound depends on how fast the object is vibrating. When an object vibrates quickly, it produces "high pitch", and when it vibrates slowly, it produces "low pitch". The rate at which an object vibrates per second is called the "frequency" of sound.

Baidu Encyclopedia-Acoustics