How fast will the electron be travelling?

[Brooke22]

How fast will the electron be travelling?

Ek = ½ MV^2
V = 2Ek/M
V = √2Ek/M
= √ 2 x 1.6x10^-19/9.1 x 10^-31
= ?
This number is too high since it implies that a larger voltage (say 10) would make the electron travel faster than light. The reason is?

 

[Galileo]

You might want to give at least SOME info about the problem and what you're trying to do.
Were you solving E=1/2mv^2 for v?

By the way. You're using the classical formula 1/2mv^2 for the kinetic energy. Ofcourse you can get velocities faster than light if you don't take relativity into account.

 

[phucnv87]

That's right. When doing with high speed, you have to apply the relative theory.[/color]

 

[topsquark]

How fast will the electron be travelling?

Ek = ½ MV^2
V = 2Ek/M
V = √2Ek/M
= √ 2 x 1.6x10^-19/9.1 x 10^-31
= ?
This number is too high since it implies that a larger voltage (say 10) would make the electron travel faster than light. The reason is?

That doesn't mean your answer might not be correct. I've found that kind of mistake in any number of Introductory level texts. Check with your instructor.

-Dan