Domanda del libro di testo
What is the wavelength, in nm, of a photon with energy (a) 0.30 eV, (b) 3.0 eV, and (c) 30 eV? For each, is this wavelength visible, ultraviolet, or infrared light?
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Ch 38: Quantization
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796
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TOC.tableOfContents
- Ch 01: Concepts of Motion35
- Ch 02: Kinematics in One Dimension75
- Ch 03: Vectors and Coordinate Systems58
- Ch 04: Kinematics in Two Dimensions60
- Ch 05: Force and Motion23
- Ch 06: Dynamics I: Motion Along a Line53
- Ch 07: Newton's Third Law27
- Ch 08: Dynamics II: Motion in a Plane52
- Ch 09: Work and Kinetic Energy56
- Ch 10: Interactions and Potential Energy50
- Ch 11: Impulse and Momentum56
- Ch 12: Rotation of a Rigid Body71
- Ch 13: Newton's Theory of Gravity52
- Ch 14: Fluids and Elasticity44
- Ch 15: Oscillations55
- Ch 16: Traveling Waves37
- Ch 17: Superposition39
- Ch 18: A Macroscopic Description of Matter53
- Ch 19: Work, Heat, and the First Law of Thermodynamics60
- Ch 20: The Micro/Macro Connection53
- Ch 21: Heat Engines and Refrigerators34
- Ch 22: Electric Charges and Forces40
- Ch 23: The Electric Field39
- Ch 24: Gauss' Law32
- Ch 25: The Electric Potential63
- Ch 26: Potential and Field57
- Ch 27: Current and Resistance42
- Ch 28: Fundamentals of Circuits39
- Ch 29: The Magnetic Field47
- Ch 30: Electromagnetic Induction60
- Ch 31: Electromagnetic Fields and Waves32
- Ch 32: AC Circuits63
- Ch 33: Wave Optics32
- Ch 34: Ray Optics57
- Ch 35: Optical Instruments30
- Ch 36: Special Relativity38
- Ch 37: The Foundations of Modern Physics25
- Ch 38: Quantization49
- Ch 39: Wave Functions and Uncertainty31
- Ch 40: One-Dimensional Quantum Mechanics35
- Ch 41: Atomic Physics18
- Ch 42: Nuclear Physics27
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796Non è quello che usi tu?Cambia libro di testo
Capitolo 38, Problema 4
Photoelectrons are observed when a metal is illuminated by light with a wavelength less than 388 nm. What is the metal's work function?
Guida verificata passo dopo passo1
Identify the key concept: The photoelectric effect relates the energy of incident photons to the work function of the metal. The work function (Φ) is the minimum energy required to eject an electron from the metal surface.
Use the equation for the energy of a photon: \( E = \frac{hc}{\lambda} \), where \( h \) is Planck's constant (\( 6.626 \times 10^{-34} \, \text{J·s} \)), \( c \) is the speed of light (\( 3.00 \times 10^8 \; \text{m/s} \)), and \( \lambda \) is the wavelength of the light in meters.
Convert the given wavelength from nanometers to meters: \( \lambda = 388 \, \text{nm} = 388 \times 10^{-9} \, \text{m} \).
Substitute the values of \( h \), \( c \), and \( \lambda \) into the photon energy equation to calculate the energy of the photon: \( E = \frac{(6.626 \times 10^{-34})(3.00 \times 10^8)}{388 \times 10^{-9}} \). This energy corresponds to the threshold energy for ejecting electrons, which is equal to the work function \( \Phi \).
Conclude that the work function \( \Phi \) of the metal is equal to the calculated photon energy, as the wavelength given represents the threshold wavelength for photoemission.
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Photoelectric Effect
The photoelectric effect is the phenomenon where electrons are emitted from a material, typically a metal, when it absorbs light of sufficient energy. This effect demonstrates the particle nature of light, where photons collide with electrons, providing them enough energy to escape the material's surface. The threshold wavelength, below which photoemission occurs, is crucial for determining the work function of the metal.
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Percorso guidato
07:40
The Doppler Effect
Work Function
The work function is the minimum energy required to remove an electron from the surface of a metal. It is a characteristic property of each metal and is typically expressed in electron volts (eV). The work function can be calculated using the equation: φ = hc/λ, where φ is the work function, h is Planck's constant, c is the speed of light, and λ is the wavelength of the incident light.
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08:30Intro to Wave Functions
Photon Energy
Photon energy is the energy carried by a single photon, which can be calculated using the formula E = hc/λ. In this equation, E represents the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength of the light. For the photoelectric effect to occur, the energy of the incoming photons must be greater than or equal to the work function of the metal.
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Percorso guidato
04:10Intro to Energy & Types of Energy
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