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Vectors -- Adding velocity vectors to make a resultant

  • #1

Homework Statement



Determine the vectors A-C, given the vectors A and C in Fig. 3-32. Vector A=44.0 at 28 degrees north of east and vector C=31.0 at 90 degrees south of east.

Homework Equations


I don't know any.


The Attempt at a Solution


44.0-31.0=11.0, 28.0-90= -62
The answers are 64.6 and 53.1 degrees.
 

Answers and Replies

  • #2
BiGyElLoWhAt
Gold Member
1,560
113
Hmmm... you took 2 vector lengths, and subtracted them. That works if they're parallel, but not at different angles.

Write your vectors in a couple different forms and post back. (I'm sure you've seen different ways to express the same vectors)
 
  • #3
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,072

Homework Statement



Determine the vectors A-C, given the vectors A and C in Fig. 3-32. Vector A=44.0 at 28 degrees north of east and vector C=31.0 at 90 degrees south of east.

Homework Equations


I don't know any.


The Attempt at a Solution


44.0-31.0=11.0, 28.0-90= -62
The answers are 64.6 and 53.1 degrees.
We don't see Fig. 3-32, but I assume you do.

First step, sketch the vectors in their given orientation so you can see what you are dealing with.

Second step, remember the rule that says to subtract a vector you can reverse its direction and add it.

BTW, you might need to brush up on your arithmetic, too. :wink:
 
  • #4
NascentOxygen
Staff Emeritus
Science Advisor
9,244
1,072
It's unusual and longwinded to describe a direction as 90 degrees South of East. Are you sure you have that specification correct?
 

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