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.
In general any place thats close to bone or nerve endings hurt the most( ribs, spine, feet) along with places that dont have too much fat to buffer the needle. Also any spots where your skin is much more sensitive will incur more pain such as the inside of your forearms and thighs, neck, head. Id imagine the butt and boob to be the least painful areas to get a tattoo since theres plenty of fat to cushion the needle. But it really depends on the individuals threshold for pain. Ive known someone who told me that it felt like a massage when they were getting their spine done.