the basic measurements of length, volume, and mass are 1 meter, 1 meter³ and 1kilogram.
One 10-millionth of the distance from the North Pole to the equator would equal one meter.
A cube with sides of one meter has a volume of one meter³.
The mass of 1,000 cubic centimeters of water is very close to (and was originally intended to be exactly) one kilograms.
but today a more precise way to define is available in which:
1 meter is defined as the distance traveled by light in 1/3×10⁸ sec.
The weight of a specific platinum-iridium prototype held by the International Bureau of Weights and Measures is defined as 1 kg.
moreover these measurements are man made and are not absolute and therefore many new units of measurement can be defined as long as they are fundamentally same everywhere.
learn more about metric system here:
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It's a chemical change since it cannot be reversed and the saliva releases a new substance
Let us assume the upstream rowing rate of Alicia = x
Let us assume the downstream rowing rate of Alicia = y
We already know that
Travelling time = Distance traveled/rowing rate
Then
6/(x + 3) = 4/x
6x = 4x + 12
6x - 4x = 12
2x = 12
x = 6
Then
Rowing rate of Alicia going upstream = 6 miles per hour
Rowing rate of Alicia going downstream = 9 miles per hour.
Answer:
I₁ > I₃ > I₂
Explanation:
Taking the pic shown, we have
m₁ = 10m₀
m₂ = 2m₀
m₃ = m₀
r₁ = r₀
r₂ = 2r₀
r₃ = 3r₀
We apply the formula
I = mr²
then
I₁ = m₁r₁² = (10m₀)(r₀)² = 10m₀r₀²
I₂ = m₂r₂² = (2m₀)(2r₀)² = 8m₀r₀²
I₃ = m₃r₃² = (m₀)(3r₀)² = 9m₀r₀²
finally we have
I₁ > I₃ > I₂
Answer:
about 14.7°
Explanation:
The formula for the angle of the first minimum is ...
sin(θ) = λ/a
where θ is the angle relative to the door centerline, λ is the wavelength of the sound, and "a" is the width of the door.
The wavelength of the sound is the speed of sound divided by the frequency:
λ = (340 m/s)/(1300 Hz) ≈ 0.261538 m
Then the angle of interest is ...
θ = arcsin(0.261538/1.03) ≈ 14.7°
At an angle of about 14.7°, someone outside the room will hear no sound.