Net Work & Kinetic Energy Video Lessons

Concept

Problem: An electron has been accelerated from rest through a potential difference of 800 V.a. What is the electron's kinetic energy, in electron volts?b. What is the electron's kinetic energy, in joules?d. What is the electron's speed?

FREE Expert Solution

The kinetic energy of electrons in electron volts:

$\overline{){\mathbf{K}}{\mathbf{=}}{\mathbf{e}}{\mathbf{V}}}$, where K is the kinetic energy, e is the electron charge, and V is the potential difference.

Kinetic energy, in terms of speed, is expressed as:

$\overline{){\mathbf{K}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{2}}{{\mathbf{mv}}}^{{\mathbf{2}}}}$, where m is mass and v is the speed.

We also need to remember that:

1eV = 1.6 × 10-19 J

a.

We use the kinetic equation K = eV

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Problem Details
An electron has been accelerated from rest through a potential difference of 800 V.

a. What is the electron's kinetic energy, in electron volts?

b. What is the electron's kinetic energy, in joules?

d. What is the electron's speed?