Troubleshooting Vectors: Finding Errors in Vector Problems | Help Requested

  • Thread starter Thread starter elpermic
  • Start date Start date
  • Tags Tags
    Vectors
Click For Summary

Homework Help Overview

The discussion revolves around a problem involving vector addition and the calculation of resultant vectors. Participants are examining the original poster's approach to combining vectors and questioning the accuracy of the results compared to a reference book.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to use the Pythagorean theorem for vector addition but questions the discrepancy between their result and the book's answer. Some participants question the validity of simply adding vectors that are not aligned in the same direction. Others suggest finding the angle between the vectors to clarify the situation.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the vector directions and the necessity of drawing a scale diagram to verify the angles involved. There is no explicit consensus on the correct approach yet, but guidance on considering the angles and directions of the vectors has been provided.

Contextual Notes

Participants note that the vectors in question may not be aligned as initially assumed, which raises questions about the original poster's calculations and the reference provided in the textbook.

elpermic
Messages
29
Reaction score
0
vectors problem, help please

Homework Statement


zkqp78.jpg




Homework Equations





The Attempt at a Solution



I used the pythagorem theorem on the first two vectors and named it vector x. It turned out to be 4.8km and I used vector x plus 3.1km of the other vector. I got 7.9km at 45 degrees NE. The book says it should be 7.8km at 38 degrees NE. What did I do wrong? OR is it the book>
 
Physics news on Phys.org


Is the resultant vector from 2.6km north and 4.0km east at a 45 degree angle from east?

If not you can't simply add 4.8km to 3.1km because they won't be in the same direction.
 


4.8 km and 3.1 km are not in the same line.
Find the angle between them.
It is equal to (45 degrees - angle between 4 km and 4.8 km.)
 


Aren't both lines( vector x and the 3.1km vector both going north east?
 


No. It is not. Draw the scale diagram and verify.
 


elpermic said:
Aren't both lines( vector x and the 3.1km vector both going north east?

Well, you went north 2.6 km, then east 4 km. To have a 45-degree angle, those two values have to be equal, which they aren't.
 

Similar threads

Needs clarity on this displacement vector diagram
  • · Replies 3 ·
Replies
3
Views
1K
Find the magnetic induction vector
  • · Replies 3 ·
Replies
3
Views
1K
Syntax Error? x and y components of E field in unit vector form
  • · Replies 13 ·
Replies
13
Views
2K
Finding force from momentum vector
  • · Replies 3 ·
Replies
3
Views
1K
Vector problem -- Find the angle between vector A and vector B
  • · Replies 8 ·
Replies
8
Views
2K
Stuck on a few Vector homework problems
  • · Replies 1 ·
Replies
1
Views
2K
Finding the expression for the x-component of velocity (vectors?)
  • · Replies 2 ·
Replies
2
Views
3K
Finding z component of a unit vector
  • · Replies 2 ·
Replies
2
Views
3K
Finding Vector Angle using cosine law
  • · Replies 13 ·
Replies
13
Views
3K
I need some clarification for a high school vectors question (accelerating bird)
  • · Replies 14 ·
Replies
14
Views
2K