The student is not correct. The uncertainty is at least
Alright, well, we can tell that this is about the , because obviously the question talks about it.
$barul(|" "stackrel(" ")DeltaxDeltap >= ℏ//2" "|)$
$Deltax$ is the uncertainty in the position.$Deltap = mDeltav$ is the uncertainty in the momentum.$ℏ = h//2pi$ is the reduced .$m$ is the mass of the bacterium in$"kg"$ .
We assume the bacterium is restricted to one dimension, and that that dimension is along the cell length.
Noting the conversions needed to get from
$color(blue)(Deltax) >= (ℏ//2)/(mDeltav)$
$= overbrace((6.626 xx 10^(-34) cancel"kg"cdot"m"^(cancel(2))"/"cancel"s" // 4 pi))^(ℏ//2)/(underbrace(1.20 xx 10^(-15) "g" xx cancel"1 kg"/(1000 cancel"g"))_(m) xx underbrace(0.0500 xx 1.00 xx 10^(-6) cancel"m/s")_(Deltav))$
$>= color(blue)(8.88 xx 10^(-10))$ $color(blue)("m")$ or$8.88 xx 10^(-4)$ $mu"m"$ .
So the student is not correct.
The uncertainty is at most