Final answer:
The ultimate tensile strength from the Brinell hardness number, you multiplied the hardness number by 10. (option B)
Step-by-step explanation:
The correct method for finding ultimate tensile strength from Brinell hardness is to multiply the hardness number by 10. Brinell hardness is a way of measuring the hardness of a material by pressing a hard ball into its surface and then measuring the size of the indentation. The Brinell hardness number can be converted into the ultimate tensile strength (UTS) of steel, assuming a suitable factor that relates the Brinell hardness to the UTS for that specific material. This approximation works for steel because the hardness and strength are related; however, it may not be as accurate for other materials. The calculation provides an estimative value of tensile strength that is useful for certain applications, even though there's not a direct quantitative relationship between them.
To get the tensile strength, the Brinell hardness number (BHN) is typically multiplied by a factor; this factor is often taken as 10 for steel, but it can vary depending on the specific material and its condition. This simplification assumes a linear correlation between the two parameters for the sake of estimations.