2 questions in Electric and magnetic fields in space.

[convict11]

Hey all I was just wondering if anyone knows how to figure out these two questions.

1) The difference in potential between the cathode and the anode of a spark plug is 1.0x10^4V. What energy does an electron give up as it passes between the electrodes?

This one I am really pretty clueless.

2) Television channel 6 broadcasts on a frequency of 85MHz. What is the wavelength of the electromagnetic wave broadcast on channel 6? What is the length of an antenna that will detect channel 6 most easily?

I read somewhere that to figure out radio wave length you take the megahertz and divide it into 300. Which works out to 3.5. I am not sure if this is the correct way to do it seems sort of simple.

If anyone could give any help would be appreciated also any sites where I can better learn the material being used would be great. Thanks.

 

[whozum]

1) Use the relationship between voltage and energy, its really simple.

2) Speed of wave = Frequency * Wavelength

Speed of wave = c = 3 x 10e8
Frequency = 85MHz = 8.5 x 10e7 Hz

 

[thepatientmental]

1) To figure out the energy an electron gives up as it passes between the electrodes, you can use the formula: E = qΔV, where E is the energy, q is the charge of the electron (1.6x10^-19 coulombs), and ΔV is the potential difference (1.0x10^4V). So, the energy would be 1.6x10^-19 x 1.0x10^4 = 1.6x10^-15 Joules.

2) You are correct in your calculation for finding the wavelength of the electromagnetic wave. The formula is λ = c/f, where λ is the wavelength, c is the speed of light (3x10^8 m/s), and f is the frequency (85 MHz). So, the wavelength would be 3x10^8 / 85x10^6 = 3.5 meters.

The length of an antenna that will detect channel 6 most easily would ideally be half of the wavelength, so in this case, it would be 1.75 meters. However, the actual length of the antenna can vary depending on factors such as the type of antenna and the surrounding environment.

Some helpful resources to learn more about electric and magnetic fields in space include NASA's website, which has a section dedicated to space physics, and Khan Academy, which offers free online courses on various topics, including electromagnetism.