The Wavelength of X-Rays Produced by 80kV Electrons

[UrbanXrisis]

X-ray tubes used by dentists can have voltages as high as 80kV to accelerate the elecrons to produce the X-rays. What is the most lowest wavelength that can be produced by such electons?

This problem seems almost too easy... i need a check

$$\lamba = \frac{1.24x10^3 V^{-1} nm}{80kV}$$

$$\lamba = 0.0155 nm$$

 

[Tide]

Check the units in your expression.

 

[UrbanXrisis]

i thought wavelengths were in nm? why do I get units of nm/v^2?

 

[inha]

the numerator should be 1240eVnm

 

[UrbanXrisis]

I am stil getting $$\lambda = 0.0155 nm$$

I used the formula $$\lambda=\frac{h*c}{80kV*e}$$

and I got the same results. am I doing this correctly?

 

[imabug]

what Tide said. Look at your units. Carefully.

 

[UrbanXrisis]

ignoring the first part, and using:

$$\lambda=\frac{h*c}{80kV*e}$$
(eV*s*m/s)/(V*m/s)

should it be in units of (eV*s)/V ?? shouldn't it be in meters?