Sorry about not using symbols but I haven't learnt how to do that yet. 1. The problem statement, all variables and given/known data A woman is on a ladder of height H. She drops small rocks of mass m toward a point target on the floor. Show that according to the Heisenberg Uncertainty Principle, the average miss distance must be at least delta(x final) = sqrt [h/pi*m] * sqrt sqrt [2H/g] where h is the planck's constant, pi is 3.14 m is the mass of the rock H is the height from which the rock is dropped g is the acceleration due to gravity. Assume that delta(xfinal ) = delta(x initial) + (delta(v))*t Also justify the assumption. 2. Relevant equations delta(x) * delta(p) < or = [h/4*pi] delta(p) = m * delta(v) v= u +at s= 0.5(u + v)t s= ut +0.5at^2 v^2= u^2 +2as 3. The attempt at a solution I did a couple of substitutions and got something like t=sqrt[2H/g] and delta(v)=sqrt[2gH] but I can't seem to get the equation needed. Tried for 2 hours and can't seem to understand it all. Please help? Or at least give some hints. Also, I don't know how to justify the assumption above.