Question

The mass of an electron is 9.11× 10–31 kg. What is the uncertainty in the position of an electron moving at 2.00 × 106 m/s with an uncertainty of Δv = 0.01 × 106 m/s?

Answer 1

Just use the Heisenberg Uncertainty principle: 

ΔpΔx = h/2*pi 

Δp = the uncertainty in momentum 
Δx = the uncertainty in position 
h = 6.626e-34 J s (plank's constant) 

Hint: 

to calculate Δp use the fact that the uncertainty in the momentum is 1% (0.01) so that 

Δp = mv*(0.01) 

m = mass of electron 
v = velocity of electron 

Solve for Δx 

Δx = h/(2*pi*Δp) 

And that is the uncertainty in position.