Answer:
The SI was and is intended to extend and refine the definitions used by the MKS.
Answer:

The Andromeda is a galaxy which is nearest to the milky way. It is also named as Messier 31 or M31 or NGC 224. It is a spiral galaxy located at a distance of approximately 2.5 million light years from earth.
another name Andromeda in Hindi is Vaikunth.
Answer:
Explanation:
For third normal mode of vibration
l =
, λ is wavelength , l is length of string .
.4 = 
λ = .267 m
velocity = 
T is tension and m is mass unit length
m = .5 x 10⁻³ / 40 x 10⁻²
= .00125 kg / m
Putting the values
velocity = 
= 253 m /s
frequency
= velocity / λ
= 253 / .267
= 947.5 Hz .