Fysiikka Flashcards
Valon nopeus
Noin 300 000 000 m/s eli
300 000 km/s
Sunnilleen miljoona kilometriä kolmessa sekunnissa.
Lähtölaukauksen aikana miljoona kilometriä.
Miljoona kertaa nopeampi kuin ääni.
Äänen nopeus
343 metriä sekunnissa eli
noin 350 m/s.
Sunnilleen kilometri kolmessa sekunnissa.
Salama on lähtölaukauksen alku ja ääni on itse laukaus.
Miljoona kertaa hitaampi kuin valo.
What is the photoelectric effect?
The photoelectric effect is a phenomenon where light causes the emission of electrons from a metal surface.
How did the photoelectric effect contribute to the concept of light as both a wave and a particle?
Einstein used the photoelectric effect to demonstrate that light can behave as a particle, called a photon, in addition to its wave behavior. The energy carried by a photon is enough to knock electrons out of a metal, a process that cannot be explained if light is only considered as a wave.
How does the energy of a photon relate to its wavelength?
The energy of a photon is inversely proportional to its wavelength. This means photons with shorter wavelengths carry more energy, and photons with longer wavelengths carry less energy.
What is the threshold frequency (or wavelength) in the context of the photoelectric effect?
The threshold frequency (or threshold wavelength) is the minimum light frequency (or maximum wavelength) required to emit electrons from a given metal. If the light’s frequency is below this threshold (or the wavelength is longer), no electrons will be emitted, regardless of the light’s intensity.
What was the purpose of the Michelson-Morley experiment?
The Michelson-Morley experiment aimed to detect the relative motion of matter through the luminiferous ether, or ‘ether wind,’ which was once believed to affect the speed of light.
What was the outcome of the Michelson-Morley experiment?
The Michelson-Morley experiment found no detectable ether wind, implying that the speed of light is independent of the motion of the observer or the source of the light.
How did the Michelson-Morley experiment contribute to our understanding of light?
The failure of the Michelson-Morley experiment to detect ether wind led to the dismissal of the concept of the luminiferous ether. It also paved the way for the theory of relativity, which posits that the speed of light in a vacuum is a constant and doesn’t require a medium to propagate.
How does the Michelson-Morley experiment relate to Einstein’s theory of relativity?
The Michelson-Morley experiment provided some of the empirical groundwork for Einstein’s theory of relativity, which includes the postulate that the speed of light in a vacuum is a constant and doesn’t depend on the motion of the observer or the source.
