Speed of Impact of electrons in a television.

In summary, the speed of impact of electrons with the screen of the picture tube can be determined by using the equation 2.48E-15 J = 1/2mv^2, where the charge of an electron is 1.6 x 10^-19 C, the mass of an electron is 9.11 x 10^-31 kg, and the potential difference is 15500 V.
  • #1
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Homework Statement



What is the speed of impact of electrons with the screen of the picture tube? Answer in units of m/s.

Electrons are accelerated through a potential difference of 15500 V
Charge of electron: 1.6 x 10^-19 C
Mass of electron: 9.11 x 10^-31 kg
Energy of electrons when they hit the screen: 2.48E-15 J

Homework Equations



v=Ed
f=ma
f=qE
K = .5mv^2

The Attempt at a Solution



I tried using that equation, I made it 15500 = .5mv^2 ... obviously plugging in the above numbers for m and v.

Computer said the answer was wrong.
 
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  • #2
Goodness they calculated the electron energy for you! Too easy!

So just use 2.48E-15 J = 1/2mv^2

Potential is the energy per charge, so you could start with V = E/q, and replace E with 1/2mv^2.
 
  • #3
No, I calculated that for a previous problem...

Thanks though, got it right now.
 

What is the "speed of impact" of electrons in a television?

The "speed of impact" refers to the speed at which electrons hit the screen of a television. This speed can vary depending on the type of television and the voltage applied to it, but is usually between 1 and 10% of the speed of light.

Why is the speed of impact of electrons important in a television?

The speed of impact determines how quickly the images on the screen can change, which affects the quality and clarity of the picture. A higher speed of impact allows for smoother and more detailed images.

How is the speed of impact of electrons measured in a television?

The speed of impact can be measured using a device called an oscilloscope, which measures the time it takes for an electron to travel from the cathode to the screen. This measurement is then converted into a speed using the known distance between the cathode and the screen.

Can the speed of impact of electrons be adjusted in a television?

Yes, the speed of impact can be adjusted by changing the voltage applied to the television. Higher voltages result in faster speeds, while lower voltages result in slower speeds. However, there are limitations to how much the speed of impact can be adjusted in a television.

How does the speed of impact of electrons affect the lifespan of a television?

The speed of impact can affect the lifespan of a television by causing wear and tear on the screen over time. Higher speeds can lead to a shorter lifespan, while lower speeds can prolong the life of the television. It is important to find a balance between speed and longevity when using a television.

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