In the Brinell hardness test of Figure 6 a 10 mm hardened-steel ball is pressed into a steel specimen under a load of 3000 kgf. The impression is measured in two perpendicular directions as shown. Using the mean diameter of the impression, determine (a) the Brinell hardness number (in HB), (b) the depth of the impression (in mm) and (c) the approximate tensile strength of the steel, taking TS ≈ 3.45 × HB (in MPa).