Q. Why it is called jack hammer?

Answer

A jack hammer is just a pneumatic or electrical tool that directly incorporates a hammer and a chisel; in Britain, it is sometimes referred to as a wrecking hammer or a pneumatic drill. William Mcreavy, who eventually sold Charles Brady King his patent, was the one who invented it. Compressed air is commonly used to power hand-held jackhammers, though some of them can also be powered by electric motors. Larger jackhammers are often hydraulically propelled, such as those that are installed on construction equipment rigs. These tools are typically used to remove rock, concrete, and pavement.