Answer
$\mathop \smallint \limits_C^{} f\left( {x,y,z} \right){\rm{d}}s = 50$
Work Step by Step
Since $f\left( {x,y,z} \right) = 10$, so the line integral is
$\mathop \smallint \limits_C^{} f\left( {x,y,z} \right){\rm{d}}s = 10\mathop \smallint \limits_C^{} {\rm{d}}s$
Since the length of the curve $C$ is 5, so $\mathop \smallint \limits_C^{} {\rm{d}}s = 5$.
Therefore, $\mathop \smallint \limits_C^{} f\left( {x,y,z} \right){\rm{d}}s = 50$.
