Uncertainty Principle Question

[lee_sarah76]

Homework Statement

Laser can now be designed to emit pulses of light smaller than 30 microns wide
in their direction of motion.

(a) Estimate the uncertainty in the momentum of a
photon in such a pulse.

(b) The momentum of a photon is p=h/λ. Estimate the
uncertainty in the wavelength of a photon in the pulse, assuming a nominal
wavelength of 800 nm.

Homework Equations

ΔxΔp ≥ h/4π, p = h/λ

h being Planck's constant of 6.626 * 10^-34 J*s

The Attempt at a Solution

My confusion with this problem stems from the fact that I'm not sure if Δx = 30*10^-6m

If that is the case, then I did Δp ≥ h/4π*Δx.

Part a: Δp ≥ 1.757 * 10^-30 kg*m/s

For part b, I then took the Δp value of 1.757 * 10^-30 kg*m/s and plugged it into p = h/λ. I then got λ = 0.000377 m.

Is this the right method?

 

[Goddar]

Seems good.