Without calculation, decide if each of the integrals below are positive, negative, or zero. Let W be the solid bounded by $z = \sqrt{x^2 + y^2}$ and $z = 5$ with $x \geq 0$.

? Positive Negative Zero  1. $\displaystyle \iiint\limits_W y \, dV$

? Positive Negative Zero  2. $\displaystyle \iiint\limits_W \left( z-5 \right) \, dV$

? Positive Negative Zero  3. $\displaystyle \iiint\limits_W x \, dV$