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German physicist Werner Heisenberg related the uncertainty of an object's position ( Δ x ) to the uncertainty in its velocity ( Δ v ) Δ x ≥ h 4 π m Δ v where h is Planck's constant and m is the mass of the object. The mass of an electron is 9.11 × 10 − 31 kg. What is the uncertainty in the position of an electron moving at 1.00 × 10 6 m/s with an uncertainty of Δ v = 0.01 × 10 6 m/s ?

Respuesta :

Answer:

The uncertainty in the position of the electron is [tex]5.79x10^{-9}m[/tex]

Explanation:

The Heisenberg uncertainty principle is defined as:

[tex]\Lambda p\Lambda x[/tex] ≥ [tex]\frac{h}{4 \pi}[/tex]  (1)

Where [tex]\Lambda p[/tex] is the uncertainty in momentum, [tex]\Lambda x[/tex] is the uncertainty in position and h is the Planck's constant.

The momentum is defined as:

[tex]p =mv[/tex]  (2)

Therefore, equation 2 can be replaced in equation 1

[tex]\Lambda (mv) \Lambda x[/tex] ≥ [tex]\frac{h}{4 \pi}[/tex]

Since, the mass of the electron is constant, v will be the one with an associated uncertainty.

[tex]m \Lambda v \Lambda x[/tex] ≥ [tex]\frac{h}{4 \pi}[/tex] (3)

Then, [tex]\Lambda x[/tex] can be isolated from equation 3

[tex]\Lambda x[/tex] ≥ [tex]\frac{h}{m \Lambda v 4 \pi}[/tex]  (4)

[tex]\Lambda x = \frac{6.626x10^{-34}J.s}{(9.11x10^{-31} kg)(0.01x10^{6}m/s) 4 \pi}[/tex]

But [tex]1J = Kg.m^{2}/s^{2}[/tex]

[tex]\Lambda x = \frac{(6.624x10^{-34} Kg.m^{2}/s^{2}.s)}{(9.11x10^{-31} kg)(0.01x10^{6}m/s) (4 \pi)}[/tex]

[tex]\Lambda x = 5.79x10^{-9}m[/tex]

Hence, the uncertainty in the position of the electron is  [tex]5.79x10^{-9}m[/tex]