Question

what is an angle grinder used to grind?
soft, porous materials
nonmetals only
imperfections in wood
hard, heavy materials

Explanation:

An angle grinder is a power tool with a rotating abrasive disc. It is designed for heavy - duty tasks. Soft, porous materials (like some foams) can be damaged by the high - speed abrasive action of an angle grinder. Non - metals only is incorrect as angle grinders can be used on metals (e.g., steel) as well. Imperfections in wood are usually sanded (using sandpaper or orbital sanders) rather than using an angle grinder which is too aggressive for most woodworking tasks. Angle grinders are ideal for hard, heavy materials such as concrete, stone, and thick metal because the abrasive disc can cut through or grind these tough substances effectively.

Answer:

hard, heavy materials