Answer:
a large matters of body with no shape is mass
Ans: A quantity cannot have units until it has dimensions. A quantity that has dimensions must have units. Yes a quantity have units but still be dimensionless for example,unit of angle is radian ,but it is a dimensionless quantity. A dimensionless quantity may have unit.
Answer:
Explanation:
For first overtone
Standing waves will be formed lengthwise and breadth-wise in the enclosures having dimension of .75m x 1.5 m
A ) For the formation of lowest two frequencies formed by standing waves along the breadth , fundamental note and first overtone may be considered.
For fundamental note ,
the condition is
wave length λ = 2L = 2 x 0.75 m
λ = 1.5 m
frequency n = v / λ
= 343 / 1.5
= 229 Hz approx
For first overtone
λ = L = 0.75m
frequency n = v / λ
n = 343 / 0.75
= 457 Hz approx
B)
For the formation of lowest two frequencies formed by standing waves along the length , fundamental note and first overtone may be considered.
For fundamental note ,
the condition is
wave length λ = 2L = 2 x 1.5 m
λ = 3 m
frequency n = v / λ
= 343 / 3
= 114 Hz approx
frequency n = v / λ
n = 343 / 1.5
= 229 Hz approx
An absorption spectrum occurs when light passes through a cold, dilute gas and atoms in the gas absorb at characteristic frequencies; since the re-emitted light is unlikely to be emitted in the same direction as the absorbed photon, this gives rise to dark lines (absence of light) in the spectrum.
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