• Subject:

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• Topic:

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One Mach number is equal to

(1) Velocity of light

(2) Velocity of sound $\left(332\text{\hspace{0.17em}\hspace{0.17em}}m/\mathrm{sec}\right)$

(3) $1\text{\hspace{0.17em}\hspace{0.17em}}km/\mathrm{sec}$

(4) $1\text{\hspace{0.17em}}m/\mathrm{sec}$