Oracle
Light travels faster in water than in a vacuum. Answer true or false.
Answer
false
- light speed
- Ordinary visible light's propagation speed in bulk liquid water, compared with its speed in vacuum.
- sources
- openstax.org, basic optics: the refractive index of water is n ≈ 1.33 (> 1), and light's speed in a medium is v = c/n, so light travels slower, not faster, in water than in a vacuum (standard physics fact, e.g. nist/codata c definition and refractive index of water at visible wavelengths)., en.wikipedia.org, hyperphysics.phy-astr.gsu.edu, nist handbook of physics and chemistry; refractive index of water ~1.33 means light speed in water is c/1.33, slower than in vacuum, nist physical measurement laboratory / standard optics references (e.g. hecht, optics): the refractive index of water for visible light is approximately 1.33, and speed of light in a medium equals c/n, so light in water travels slower than in vacuum, not faster, nist/codata physical constants and standard optics references (e.g. hecht, optics): refractive index of water n ≈ 1.33 means light's phase velocity in water is c/n ≈ 225,000 km/s, slower than the vacuum speed of light c ≈ 299,792 km/s., nist/codata physical constants and standard optics references (e.g. hecht, optics): the refractive index of water for visible light is approximately n = 1.33, giving v = c/n ≈ 2.25×10^8 m/s, which is slower than c = 2.998×10^8 m/s in vacuum, nist/codata physical constants and standard optics references (e.g. hecht, optics): water has refractive index n ≈ 1.33 at visible wavelengths, so light's speed in water is c/n ≈ 2.25×10^8 m/s, slower than its vacuum speed c ≈ 3.00×10^8 m/s, nist/codata physical constants and standard optics references (e.g. refractive index of water n ≈ 1.33) establish that light slows down when passing from vacuum into water, since v = c/n and n > 1 for water, nist/codata physical constants and standard optics references (e.g. refractiveindex.info) give water's refractive index n ~= 1.33 at visible wavelengths; since velocity = c/n < c, light travels slower, not faster, in water than in vacuum., nist/codata physical constants and standard optics references (e.g., hecht, "optics"): the refractive index of water is ~1.33, so light's speed in water (v = c/n) is slower than in vacuum, not faster., nist/codata physical constants and standard optics references (e.g., hecht, optics) give the refractive index of water as n≈1.33; since phase velocity v = c/n, light is slower in water than in vacuum, nist/codata physical constants: refractive index of water n ≈ 1.33 (>1), so light's speed in water v = c/n ≈ 2.25×10^8 m/s, slower than c ≈ 3×10^8 m/s in vacuum, nist/codata physical constants: refractive index of water n ≈ 1.33 implies light speed in water v = c/n < c, i.e. light is slower in water than in vacuum, nist/encyclopedia britannica physics reference: refractive index of water (~1.33) means light travels at approximately c/1.33 (~2.25×10^8 m/s) in water, slower than c (~3×10^8 m/s) in vacuum, nist/physics constants: speed of light in water = c/n ≈ 2.25e8 m/s, slower than vacuum c = 2.998e8 m/s (encyclopaedia britannica, refractive index of water), nist/physics reference: speed of light in water v = c/n where n ≈ 1.33, so v ≈ 2.25×10^8 m/s, which is slower than c = 2.998×10^8 m/s in vacuum, nist/physics standard: refractive index n = c/v, so light's speed in a medium is v = c/n; water's refractive index (~1.33) is greater than 1, meaning light travels slower in water than in vacuum, not faster., nist/physics textbook fact: refractive index of water n ~= 1.33, so light speed in water v = c/n ~= 2.25e8 m/s, which is slower than c in vacuum (2.998e8 m/s), nist/refractive index physics: water's refractive index n ≈ 1.33, and light's phase speed in a medium is c/n, so light is slower in water than in vacuum, nist/standard physics references on refractive index of water (n ≈ 1.33), e.g. https://physics.nist.gov and standard optics textbooks (hecht, optics), which give light's speed in a medium as v = c/n, so light travels slower in water than in vacuum, nist/standard physics: refractive index of water n ~ 1.33; speed of light in a medium v = c/n, so light travels slower in water than in vacuum, nist/standard physics: refractive index of water n ≈ 1.33, so light's speed in water is c/n ≈ 0.75c, slower than in vacuum, refractive index of water (~1.33, nist/codata-consistent physical constants) implies light's phase velocity in water is c/n ≈ 0.75c, slower than in vacuum., science.nasa.gov, the feynman lectures on physics, vol. i, chapter 31, section 31-1: https://www.feynmanlectures.caltech.edu/i_31.html, www.feynmanlectures.caltech.edu, www.nist.gov, www.physicsclassroom.com
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- pinnedblocks 26,083,605 to 26,083,905 to · on Ethereum mainnet
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#1193falsefrom openstax.org
#1566falsefrom openstax.org
#735falseNIST/physics reference: speed of light in water v = c/n where n ≈ 1.33, so v ≈ 2.25×10^8 m/s, which is slower than c = 2.998×10^8 m/s in vacuum
#1631falsefrom www.nist.gov
#429falseNIST Handbook of Physics and Chemistry; refractive index of water ~1.33 means light speed in water is c/1.33, slower than in vacuum70 more
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