Answer:
Explanation:
The speed of sound in the air increases 0.6 m / s for every 1 ° C increase in temperature. An approximate speed can be calculated using the following empirical formula:
Where:
A more exact equation, usually referred to as adiabatic velocity of sound, is given by the following formula:
Where:
Hence:
Now, the Mach number at which an aircraft is flying can be calculated by:
Where:
Therefore:
The star is FARTHER from Earth than the limit of our ability to measure parallax.
The NEAREST star outside the solar system has a parallax angle of 0.742 SECOND. That's like 0.000206 of a degree ! ALL other stars have SMALLER parallax.
I have no idea how they measure angles like these ... especially when the change in direction takes six months to happen !
F=-kx
so multiple the two numbers together and put a negative sign in front
F=-19.25
Not sure the precise concept of "normal observation", but I assume that is observed by "eyes".
Eye observation is basically macroscopic, but when you use a mark, which can be regarded as a point of mass, then it goes to microscopic.
Mark is a reference point which you can compare the relative position change, but with your eyes, first you cannot notice microscopic changes, second the eyes cannot precisely set a stable reference point.
