You are an engineer designing a switch that works by the photoelectric effect. The metal you wish to use in your device requires 6.7x10 (to the -19 power. J/atom to remove an electron. Will the switch work if the light falling on the metal has a wavlength of 540nm or greater? Why or why not?
Radiation in the ultraviolet region of the electromagnetic spectrum is quite entergetic. It is this radiation that causes dyes to fade and your skin to burn. If you are bombarded with 1.00 mol of photons with a wavelength of 375nm, what amount of energy (in kilojoules per mole of photons) are you being subjected to?
What is the shortest wavelength photon an excited H atom can emit? Explain briefly.© BrainMass Inc. brainmass.com October 24, 2018, 5:37 pm ad1c9bdddf
All of your questions revolve around the photon theory of light, originally discovered by Max Planck in 1900 and expanded upon by Einstein in 1905. The crux of the theory is the fact that light can be modeled as a dicrete set of packets, called photons. Each packet carries a finite amount of energy which is specifed by the Planck relationship, which states:
Energy of a photon = Planck's Constant * frequency of light.
Thus the energy carried by light is directly proportional to its frequency. Therefore, blue light is more energetic than red light, because its frequency if higher. This idea immediately answers your first two questions if we also recall that the frequency of light, like any wave, is related to its wavelength by the equation:
frequency x wavelength = speed of the wave
or specificially for light:
frequency x wavelength = speed of light (which is 3.00 E 8 m/s)
(note the 3.00 E8 is my notation for 3.0 x 10^8)
In your first question your device needs 6.7E-19 J/atom to remove an electron from the atom. Where does this energy come from? It comes from a photon of light hitting the device and imparting its energy to it. Thus the energy of each photon hitting the ...
The solution is given step-by-step in approximately 500 words.
Assorted Physics Questions
1. What conditions must be met to produce simple harmonic motion?
2. As you pass a semitractor-trailer on an interstate, you notice that its trailer is bouncing up and down slowly. Is it more likely that the trailer is heavily loaded or nearly empty? Explain.
3. When sound passes from one medium to another where its speed is different, does its frequency or wavelength change? Explain briefly.
4.Dolphins make sounds in air and water. What is the ratio of the wavelength of a sound in air to its wavelength in water? Assume the air temperature is 20.0 degrees C. (Hint: you must look up the speed of sound in air and in water to answer this question.)
5. Radio waves transmitted by an FM transmitter have a frequency of 89.90 MHz. What is the wavelength of these waves? (Radio waves, like all electromagnetic waves, travel at the speed of light.)
6. Consider the equation
f(x) = A sin(kx - omega t)
where I have used the word "omega" instead of the Greek symbol, on account of browser compatability problems. This describes a wave propagating along the x-axis. (A) What is the meaning of the constant "A"? (B) Is this wave traveling in the positive direction or the negative direction? (C) "k" is called the propagation number (and has other names.) If "k" has a value of 12.6 per meter, what is the wavelength of the wave? (D) "Omega" is called the angular frequency. If "omega" has a value of 400 radians per second, what is the frequency ("f") of the wave?
7. What happens to the intensity of a wave if you double the amplitude, "A"?View Full Posting Details