1. The problem asks for the northward speed over the ground in part B. 2. To find the northward speed over the ground, we need to consider the velocity components involved. 3. Typically, if a plane or object moves with a velocity vector, the northward component is the projection of that velocity onto the north direction. 4. If the velocity vector is given as $\vec{v} = v_x \hat{i} + v_y \hat{j}$, where $\hat{j}$ points north, then the northward speed is $v_y$. 5. Without specific values or vectors from part B, the general formula for northward speed is the magnitude of the velocity component in the north direction. 6. If the problem involves wind or other vectors, sum the vectors first and then extract the northward component. 7. Please provide the velocity vectors or data from part B for a precise calculation.