Hertz is the number of cycles per second in an oscillating wave form. So 60Hz has 60 identical cycles in 1 sec. An Ampere (amp, or A) is the amount of electrons (or charge) that flow past a certain point in one seconds. So amperes are Coulombs/second.
The most and the least painful places to get a tattoo. Shoulder. The shoulder is the least painful tattooing site for two main reasons. First, because in this area there is a greater amount of muscle and second â nerves are not so much sensitive as in other nooks of the body. This area is often the most used and first timers tend to opt for them.
Very safe: One of the benefits of using that locations for injections is that it's a very safe location. Not at all likely to damage anything. The main drawback is that injection in that location is typical very painful with several days of significant aching.