Vector Addition: Finding Displacement

In summary, the speaker is seeking help with their homework, specifically with finding the displacement of a family on vacation. They have found the X and Y components of each vector and tried to use the Pythagorean theorem, but are having trouble with their calculations. Another person responds and points out an error in the speaker's X and Y components.
  • #1
C42711
22
0
I am having a lot of trouble with my homework. If anyone could help me, it would be much appreciated.

The Smith's go on vacation. They travel 16.0 km north/west; then turn 27 degrees to the left and go 135 km; then 294 km south/west. What is their displacement from home?

So I found the X and Y components (using trig functions) of each vector and added them. I then tried to put those numbers into the Pythagorean theorem, but it's not working. I think my X and Y components are wrong. I got the Xs to equal 69 and the Ys to equal 155.3. This is the diagram I made: (the numbers that were given are in red, the rest I found, not sure if they are right though)
[PLAIN]http://img257.imageshack.us/img257/7742/78747381.png
By c42711 at 2011-10-30
 
Last edited by a moderator:
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  • #2
Yes, something wrong with those x y components. The 294 SW vector has x component 294*cos(45) = 208 west. So your total of 69 is way too small. Got your calculator set on degrees? Note that two of the y components are north while the third one is south.
 

Related to Vector Addition: Finding Displacement

1. What is vector addition?

Vector addition is a mathematical operation that combines two or more vectors to find a resultant vector. It involves adding the magnitudes and directions of each vector to find the overall displacement.

2. How do you find the displacement using vector addition?

To find the displacement using vector addition, you need to first draw a diagram of the vectors, with their magnitudes and directions. Then, add the vectors head-to-tail and draw the resultant vector from the tail of the first vector to the head of the last vector. The magnitude and direction of the resultant vector will give you the displacement.

3. What are the rules for vector addition?

The rules for vector addition are:
- Vectors can be added in any order
- The magnitude and direction of a vector remain the same regardless of its position
- The resultant vector is the sum of the individual vectors
- The resultant vector is drawn from the tail of the first vector to the head of the last vector.

4. Can you use vector addition for 3 or more vectors?

Yes, vector addition can be used for any number of vectors. When adding 3 or more vectors, you can either add them in pairs or use the head-to-tail method to add them one at a time. The end result will be the same.

5. What are some real-life applications of vector addition?

Some real-life applications of vector addition include:
- Navigation and mapping
- Air traffic control and flight paths
- Projectile motion and trajectory calculations
- Forces and motion in physics
- Components of motion in sports and athletics.

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