Determine the resultant at 21N east and 85N south

To determine the resultant at 21N east and 85N south, we need to use vector addition.

First, let's draw a coordinate grid. In this case, we will use a standard xy-plane, where the positive x-axis represents east and the positive y-axis represents north.

Now, let's analyze the given vectors:

1. The vector 21N east: This means that the vector has a magnitude of 21 units and points towards the east direction. So, on the coordinate grid, we can represent this vector as (+21, 0), since it only has an x-component.

2. The vector 85N south: This means that the vector has a magnitude of 85 units and points towards the south direction. So, on the coordinate grid, we can represent this vector as (0, -85), since it only has a y-component.

To find their resultant, we need to add these two vectors. To do this, we add the x-components and add the y-components of the vectors separately.

Adding the x-components:
21 + 0 = 21

Adding the y-components:
0 + (-85) = -85

So, the resultant vector has an x-component of 21 and a y-component of -85. Therefore, the resultant at 21N east and 85N south can be represented as the vector (+21, -85).