Quantum physics (quantum theory, quantum mechanics)

HW 3, cont’d
HW3.2: uncertainty: consider two objects, both
moving with velocity v = (100±0.01)m/s in the x-
direction (i.e. v x = 0.01m/s); calculate the
uncertainty x in the x – coordinate assuming the
object is
• (a) an electron
(mass = 9.11x10 -31 kg = 0.511 MeV/c 2 )
• (b) a ball of mass = 10 grams
• (c) discuss:
o does the electron behave like a “particle” in the
Newtonian sense? Does the ball?
o Why / why not?
o hint: compare position uncertainty with size of object;
(size of electron < 10 -18 m, estimate size of ball from its
mass)
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