1. The Shocking Truth Electric Shock Science

2. What About You? Turn to a partner and tell of a time you received an electric shock. If you know the voltage involved, tell that

3. Measuring Body Resistance Hold the leads of a multimeter in both hands. Make sure the meter is on the 2000k scale (reads up to 2 million ohms) The reading will be in thousands of ohms. ie a reading of 673 means 673,000 ohms Divide the reading into 120Volts Example 120V/1,200,000  0.0001  A = 0.1ma (record in your notes) Repeat with wet hands

4. Shock Hazards 1 ma (milliampere) can be felt A few ma can be painful More than 10 ma causes muscles to contract – you may not be able to let go! And, you may not be able to breathe and could die. Artificial respiration could revive you. Above 50-70 ma (AC) through the heart for one second may cause heart muscles to contract irregularly (ventricular fibrillation) and not pump effectively. Fibrillation is very hard to stop

5. Using a Defibrillator Could Get Your Heart to Pump Properly Again

6. Strange But True Larger currents, around 1 Amp stop the heart completely! When the current stops, the heart usually starts beating again But larger currents also cause burns and tissue damage, especially with voltages around 500-1000 volts

7. Meet “Old Sparky” Electric chair used at Sing Sing prison in New York Up to 2450 volts AC was used

8. Why AC is more deadly Human body acts as if it had capacitance in parallel with its resistance This provides an additional path for current to flow Also AC is more likely to cause fibrillation R C

9. Common Causes of Shocks faulty wiring, electrical overloads, damaged cords, sagging power lines, exposure to power lines, failure to de-energize, lack of warning or shielding devices