A person walks 10km north 20 km east and 10 south the resultant displacement is ?
This seems more like geometry than science. I would figure out his final coordinates and then use Pythagorean theorem.
10 N and 10S means no N-S displacement, right?
To find the resultant displacement, we need to find the total distance and direction from the starting point to the ending point.
In this case, the person first walks 10 km north. Then, they walk 20 km east. Finally, they walk 10 km south.
To visualize their movement, we can draw a diagram:
↑
10 km
|
←---X---→
10 km | 20 km
↓
We can see that the person is 10 km north of the starting point, and they have moved 20 km to the right. To find the resultant displacement, we need to find the net distance and direction from the starting point to the ending point.
Using Pythagoras' theorem, we can calculate the net distance:
Net distance = square root of((10 km)^2 + (20 km)^2)
= square root of(100 km^2 + 400 km^2)
= square root of(500 km^2)
≈ 22.36 km
To find the direction, we can use trigonometry.
tan(angle) = opposite / adjacent
tan(angle) = 10 km / 20 km
angle ≈ tan^(-1)(0.5)
angle ≈ 26.57 degrees
Therefore, the resultant displacement is approximately 22.36 km in the northeast direction (26.57 degrees from north).