1 Charged Rod L A metal rod of length L = 30 cm has been charged up for a physics demonstration. It has total charge Q = 5 µC uniformly distributed along its length. (a) What is the electric potential distance x = 1 mm from one end of the rod? (b) The dielectric strength of air is 3 x 10° v/m. This is the electric field strength at which air molecules are ripped apart and air becomes a conductor instead of an insulator. That is to say, you get a spark! You are a "grounded" conductor, so the potential of your fingertip is V = 0V. Use your result from part (a) to estimate about how close can you bring your finger to the end of this rod before you get zapped.

1 Charged Rod L A metal rod of length L = 30 cm has been charged up for a physics demonstration. It has total charge Q = 5 µC uniformly distributed along its length. (a) What is the electric potential distance x = 1 mm from one end of the rod? (b) The dielectric strength of air is 3 x 10° v/m. This is the electric field strength at which air molecules are ripped apart and air becomes a conductor instead of an insulator. That is to say, you get a spark! You are a "grounded" conductor, so the potential of your fingertip is V = 0V. Use your result from part (a) to estimate about how close can you bring your finger to the end of this rod before you get zapped.