Speed of Impact of electrons in a television.

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SUMMARY

The speed of impact of electrons on a television screen can be calculated using the kinetic energy formula. Given that electrons are accelerated through a potential difference of 15500 V, their energy upon impact is 2.48E-15 J. By applying the equation 2.48E-15 J = 1/2 mv^2, where the mass of an electron is 9.11 x 10^-31 kg, the correct speed can be determined. The initial attempt to solve the problem using the potential difference directly was incorrect, but the correct approach involves equating kinetic energy to the energy derived from the potential difference.

PREREQUISITES
  • Understanding of kinetic energy equations
  • Familiarity with basic physics concepts such as potential difference and charge
  • Knowledge of electron properties, including mass and charge
  • Ability to manipulate algebraic equations
NEXT STEPS
  • Study the relationship between potential difference and kinetic energy in charged particles
  • Learn about the principles of electron acceleration in cathode ray tubes
  • Explore advanced topics in electromagnetism related to charged particle motion
  • Investigate the effects of varying potential differences on electron speed
USEFUL FOR

Students studying physics, particularly those focusing on electromagnetism and particle dynamics, as well as educators looking for practical examples of kinetic energy applications in electronics.

Yavko2510
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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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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.
 
No, I calculated that for a previous problem...

Thanks though, got it right now.
 

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