Short Answer

$$\text { Use spherical coordinates to evaluate } \iiint _ { B } \sqrt { x ^ { 2 } + y ^ { 2 } + z ^ { 2 } } d V \text {, where } B \text { is the ball } x ^ { 2 } + y ^ { 2 } + z ^ { 2 } \leq 6 \text {. }$$