1. The problem statement, all variables and given/known data These questions are out of Modern Physics by Tipler. I feel like I'm close to the answer but missing something small. #1: A ladybug 5mm in diameter with a mass of 1 mg being viewed through a low power magnifier with a calibrated reticule is observed to be stationary with an uncertainty of 10^-2 mm. How fast might the ladybug actually be walking? #2 Protons and neutrons in nuclei are bound to the nucleus by exchanging pions ( pi mesons) with each other. This is possible to do without violating energy conservation provided the pion is reabsorbed within a time consistent with the Heisenberg uncertainty relations. Consider the emission reaction p --> p + where m = 135 MeV/c2. A: Ignoring kinetic energy, by how much is energy conservation violated in this reaction? B: Within what time interval must the pion be reabsorbed in order to avoid the violation of energy conservation? 2. Relevant equations ΔXΔP ≥ ħ/2 ΔE*τ ≥ ħ 3. The attempt at a solution For #1: I said that since the uncertainty is .01mm the lower boundary(lowest possible measurement for the diameter) is (5 - .01)mm and the upper boundary is (5+.01)mm. so: ΔP≈ ħ/2(ΔX) (For both X's. You'll get 2 values for P) Then saying P=MV. so V ≈ ħ/2(M)(ΔX) for both X's. For #2: I said that the conservation is violated by the rest energy of one pion. Because p ---> p + π is the reaction. but I'm not sure what to use for the uncertainty for E (ΔE) in: τ ≥ ħ/ΔE My best! Thanks!