U.S. PRESIDENTS VIVE LE RESISTANCE ELECTRICAL SAFETY 30 KV ABOVE GROUND “OHM” MY! WHO WAS PRESIDENT WHEN ELECTRICITY WAS INSTALLED IN THE WHITE HOUSE? BENJAMIN HARRISON What is the canonical value of resistance for a human gripping two tips of a multimeter? 500 kW I’m a resistor; you’re a resistor! Hooray, we’re all resistors! 2013 Circuit class resistance (gripping tips of ohmmeter probes with dry skin): Mean +/- std. dev 1.3 +/- 1 Mohm Range: 105 kOhms – 3.2 MOhm Canonical value: 500 kW (a reasonable ‘back of the pocket’ number to carry around) Franco Colombo on Venice Beach circa 1960 WHAT UNIV. OF CALIFORNIA PROF STUDIED THE EFFECTS OF ELECTRICAL CURRENT ON ELICITING INVOLUNTARY MUSCLE MOVEMENT WHO LATER INVENTED THE GFCI? CHARLES CHARLESDALZIEL DALZIEL “Don't think it's conductive? Go stand outside in your bare feet and hold a hot wire. But before you do make funeral arrangements.” -Bill Marsden Is the bird shocked? Why or why not? Draw the circuit diagram and explain Never ever remove it! Hot wire in contact with metal case due to wear over time Can a toaster dropped into a bathtub electrocute you? Crap….I dropped my toaster in the bathtub again Develop an approximate circuit model a person soaking in a bathtub with an electrical appliance in contact with the water, then… "I figured if I had the stamina to run four marathons, I could take the brunt a good-humored 10,000 volt shock. Not quite. "The obstacle, the last of a few dozen, was 50 yards from the finish line. What made it worse: There was a wait. A line formed so we could watch people run through 50-60 dangling wires that charged with electricity every three seconds… "When it was my turn, I took off fast hoping to power my way through. "The first shock hurt like hell. If you've ever been shocked before, you know how it feels. Intense pin-prickling pain is followed by your extremities involuntarily flailing in all directions. "The second shock just about sent me to the ground. Mind you, we were running over hurdles of dirt through the 20 feet of live cables. I almost made it until the third shock hit. My legs left the ground and sent the rest of my body face first into the wet mud. http://howelectricityworks.weebly.com/ http://science.nationalgeographic.com/science/photos/heart/ http://www.physics.ohio-state.edu/~p616/safety/fatal_current.html allaboutcircuits.com Loyalkng.com http://www.aikencolon.com/Fluke-1630-Earth-Ground-Clamp-Meter-Tester-TestEquipment_p_3119.html http://www.youtube.com/watch?v=PXvCLMcFVBY&feature=related (bolt of lightning) http://toughmudder.com/obstacles/electroshock-therapy/