Calculating Displacement
We can use this applet to help practice calculating the displacement from an initial position to a final position. You can move the red Initial and Final pointers to positions A, B, D and F. They should snap to the grid at nice whole number coordinates, but if they don't, move them a small distance away and try again.
The check boxes will reveal the x displacement, the y displacement, the magnitude of the resultant and the Direction.
To calculate the magnitude and direction of each vector you must first determine the x displacement and the y displacement. If you choose points A,B, D and F, you may get away with counting squares here, but practice your subtraction ( and ) because that method will always work, not just here.
Direction can be found using your tangent ratio . This will give you the answer shown when you click the Direction checkbox which will always be "North of" or "South of.." You may end up determining the complimentary angle (90) "West of ...." or "East of.." and that would also be correct.
You can review the course material examples.
1. Move Initial pointer to A (-8, 3) and Final pointer to B(-3, -1). Determine the resultant vector algebraicallly and check.
2. Move Initial pointer to D (3, 2)and leave Final pointer at B (-3, -1). Determine the resultant vector algebraically and check.
3. Move Initial pointer to F (12, -6) and Final pointer to D (3, 2). Determine the resultant vector algebraically and check.
4.. Move Initial pointer to B and leave Final pointer at D. Determine the resultant vector and check.
5. Move Initial and Final pointers to any point other than A, B, D or F for a more challenging problem. Determine the resultant vector and check.