Physics 012 1st Edition Lecture 39 Outline of Last Lecture II. Length Contractiona. Proper length (L0): distance between two points measured by an observer at rest relative to these two pointsi. L = L0/γii. Ex) Pole in a barn paradox: A runner is moving at 0.75c carrying a pole 15m long toward a barn that is 10 m wide. A ground observer (stationary relative to the barn) can open and close both doors simultaneously via remote control. Will the pole fit in the barn?1. For ground observer: Lpole = L0/γ = 15 m √(1-[(0.75c)2/c2]) = 9.9 ma. Pole will fit in barn (9.9 m < 15 m).2. For runner: Lbarn = L0/γ = 10 m √(1-[(0.75c)2/c2]) = 6.6 ma. Pole will not fit in barn (10m > 6.6m).3. Simultaneity is not constant, but is relative. Even though the barn doors close simultaneously for the stationary observer, they do not close simultaneously for the runner. For the runner, there is always one door open where the pole can stick out of.b. Relativistic Addition of Velocitiesi. vAC = (vAB + vBC)/(1+[vABvBC/c2]Outline of Current Lecture III. Review: Lenses and MirrorsLens Mirrorsdi negative Virtual image, same side as object,uprightVirtual image, behind mirror, uprightf negative Diverging (double concave) Convexm negative Inverted image Inverted imageIV. Review: Relativistic Energya. E = mc2/√(1-[v2/c2])b. Kinetic energy = E – E0These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. E0 = rest energy (energy associated with anything with mass)V. Review: RC Circuitsa. τ = RCb. For parallel plate capacitor: C = Aε0/dVI. Review: Conservation of Linear Momentuma. m1v1 =
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