Answer :
Final answer:
The common types of stationary grinders are a bench grinder and a pedestal grinder. They are used in various grinding tasks, unlike the ancient grinding tools studied by Jennie Ebeling and Yorke Rowan, which processed food and materials like cereals, nuts, and minerals using mortars, pestles, and grinding slabs.
Explanation:
The two common types of stationary grinders are: a) Bench grinder, pedestal grinder. A bench grinder typically sits on a workbench and is used for a variety of grinding tasks, such as shaping metal tools or sharpening blades. A pedestal grinder is similar in function but is mounted on a stand or pedestal, which may be bolted to the floor for stability.
By contrast, an angle grinder and die grinder, listed in option b), are handheld power tools used for grinding and polishing. A belt grinder and a disc grinder, mentioned in option c), which are also stationary machines, are commonly used for sanding and finishing surfaces. The options d) do not represent common grinding devices; a jigsaw is a tool for cutting shapes in wood or metal, and a reciprocating grinder does not exist as a standard tool.
In comparison to the ancient grinding tools studied by archaeologists Jennie Ebeling and her colleague Yorke Rowan, modern stationary grinders serve somewhat different functions. The early tools involved mortars and pestles for hand grinding and later on, hand stones and grinding slabs. These ancient grinders were used for processing a variety of materials including nuts, cereals, meat, bark, minerals, salt, and herbs, as discovered through residue studies.
