# Wavelength of an electron

You just need to round the answer to the correct number of significant figures. The answer should be 0.727 x 10^-3 meters.

## Homework Statement

What is the corresponding wavelength, in meters, of an electron moving at 1 m/s?
Velocity: 1 m/s
Planks Constant = 6.626 069 57 x 10^-34
Mass of electron = 9.109 382 91 x 10^-31
Momentum = unknown

## Homework Equations

We need to find momentum to use De Broglie's equation.

Momentum = Mass * Velocity
De Broglie's Equation for finding the wavelength: λ = h/p
h being the Planck constant

## The Attempt at a Solution

My attempt.

Finding momentum : P = 9.109 382 91 x 10^-31 * 1 m/s
p = 9.109 382 91 x 10^-31
finding the wavelength
First divide the numbers WITHOUT the exponent
so 6.626 069 57/9.109 382 91 = 0.727 389 51
now exponents -34/-31
= -3 (I took out the extra steps)

final answer λ = 0.727 389 51 x 10^-3

is this correct?

Last edited:
1. First divide the numbers WITHOUT the exponent
so 6.626 069 57/9.109 382 91 = 0.727 389 51
now exponents -34/-31
= -3 (I took out the extra steps)

final answer λ = .0727 389 51 x 10^-3

is this correct?

No.
How did you get from 0.727 389 51 to .0727 389 51 ?

rude man said:
No.
How did you get from 0.727 389 51 to .0727 389 51 ?

Oh crap ! MY bad human error it is a typo!

Last edited:
Oh crap ! MY bad human error it is a typo!

Thought so! But instructors mark off for those too!

rude man said:
Thought so! But instructors mark off for those too!

Haha I will be more weary next time! So does the math look off? :tongue:

Math is fine.