I'm so confused of the Heisenberg's Uncertainties... Here's a question i have to solve, although it looks very easy but my understanding of Heisenberg's Uncertainties is still shallow. Fuzzy a quantum mechanical duck lives in a world which h = 2 PI Js. Fuzzy has a mass of 2.0 kg and initially is known to be within a pond of 1m wide. - The minimum uncertainty in his speed? - Assuming the uncertainty in speed prevails for 5.0s, determine uncertainy in position after that time. This is my attempt to solve the first one: Of course I have to apply Heisenberg's Uncertainties here. m x (uncertainties in speed) x (uncertainties in location) => h/4PI the mass is 2.0kg, but the uncertainty in location, is it half of the width or it's the width?? I'm still not good in determining the uncertainties.