Answer
$25.1mi/h$, N $4.6^{\circ}$ W
Work Step by Step
Step 1. Identify the walking vector as $\vec {v_w} =-2i$
Step 2. Identify the liner moving vector as $\vec {v_l} =25j$
Step 3. The true vector of the total movement is the sum of the above two vectors: $\vec {v_t} =\vec {v_w} +\vec {v_l} =-2i+25j$
Step 4. The true speed is the modulus of the velocity: $|\vec {v_t} |=\sqrt {(-2)^2+(25)^2}\approx25.1mi/h$,
and direction of the vector with respect to the $+x$-axis is $\theta=tan^{-1}\frac{25}{-2}\approx94.6^{\circ}$ or N $4.6^{\circ}$ W
