Answer:
Velocity of electron along x direction is 57.9 m/s
Explanation:
The uncertainty in x coordinate of electron, Δx = 0.200 mm = 0.2 x 10⁻³ m
Let vₓ be the x component of electrons velocity.
The uncertainty in x component of electrons momentum is:
Δpₓ = mΔvₓ
Here m is mass of the electron.
The uncertainty in velocity x component is 1% i.e. 0.01.
So, the above equation can be written as :
Δpₓ = 0.01mvₓ ....(1)
The minimum uncertainty principle is:
....(2)
Here h is Planck's constant.
From equation (1) and (2),

Substitute 0.2 x 10⁻³ m for Δx, 9.1 x 10⁻³¹ kg for m and 6.626 x 10⁻³⁴ m²kg/s in the above equation.

vₓ = 57.9 m/s