It is a harder metal, and if the coating isn't done right, and excessive coating is put on, it can cause malfunctions... AR rifles have very tight tolerances, and aren't forgiving of things such as that.
The 1943 Lincoln cent is zinc coated steel not nickel and copper.
To prevent rust & wear.
There is no bicycle that is made out of Nickel. Some steel frames may be coated with Nickel only for aesthetic purposes.
Since 1965, U.S. quarters have been made of nickel-coated copper (91.67% copper and 8.33% nickel).
The 1943 Lincoln cent is zinc coated steel not nickel and average values are 5 to 10 cents
It's silvery in color, but modern ones are copper coated in nickel.
third world country black markets...
Since 1971, U.S. half dollars have been made of nickel-coated copper (91.67% copper and 8.33% nickel).
The aircraft carrier has a greater kinetic energy because it is so much more massive. Kinetic energy = (1/2)mv2, where m is mass and v is velocity.
Older coins were made of different metals, such as silver or copper. Coins that used to be silver are now nickel or nickel-coated copper, and coins that were copper are now copper-coated steel or zinc.
Cents are made out of copper-coated zinc (post-1982), modern dollar coins are made out of brass.
Stainless steel is coated in a Zinc Chromium alloy which oxidises and creates a protective layer covering the steel and preventing it from rusting. stainless steel doesn't corrode because it's coated in chromium nickel.