Posted by **Anonymous** on Saturday, December 11, 2010 at 4:05pm.

a boat starts at point A, moves 3km due north, then 2 km due east, then 1 km due south, and then 4 km due east to point b. Find the distance AB

- Math -
**MathMate**, Saturday, December 11, 2010 at 6:05pm
Add up each component (north or east) separately, and finally find the distance by the vectorial sum (using Pythagoras).

North: 3-1=2km

East: 2+4=6

Distance = √(2²+6²)

=√(40)

=2√(10)

- Math -
**Triquenita**, Saturday, December 11, 2010 at 7:41pm
I don't understand where for North you put 3-1. The boat moved 1km South and 3km North. Is that how this was done?

- Math -
**MathMate**, Saturday, December 11, 2010 at 9:05pm
In vectors, directions are *signed*.

This means that if we take the positive direction as north, then going south is backwards, and is thus represented as negative. Otherwise it would not make a difference between going 3 km north and 1 km north (3+1), and going 3 km north and 1 km south (3-1).

Hope that clarifies how it's done.

- Math -
**efrata**, Thursday, October 2, 2014 at 2:08pm
similar to other

## Answer this Question

## Related Questions

- math - what distance formula would you use to solve this problem? A boat starts ...
- math - A boat starts at point A, moves 3 km due north, then 2 km due east, then ...
- math - a boy travels 15 km due north,then goes 9 km due east,then 3km due south....
- Geometry - A boat starts at point A, moves 3 km due north, then 2 km die east, ...
- Physics - I am having trouble figuring out this question: Part 1: A long staight...
- Phys 2 - I am having trouble figuring out this question: Part 1: A long staight ...
- math - a boat starts at point a p travels 15 miles due north to point r then ...
- Please Please Help-Physics - I am having trouble figuring out this question: ...
- physics - A 316-kg boat is sailing 12.0° north of east at a speed of 1.60 m/s. ...
- Physics - A 343-kg boat is sailing 16.2° north of east at a speed of 1.98 m/s. ...