- #1
Maximillien
- 8
- 0
Draw the vectors head to tail so they make a triangle
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Draw the vectors head to tail so they make a triangle
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Homework Help Overview
The discussion revolves around drawing vectors head to tail to form a triangle, specifically focusing on vector magnitudes and angles. The problem involves understanding vector addition and the relationships between the sides and angles of a triangle formed by these vectors.
Discussion Character
- Exploratory, Assumption checking, Problem interpretation
Approaches and Questions Raised
- Participants discuss how to represent vectors graphically, particularly in relation to their magnitudes and angles. There is uncertainty about using trigonometric laws versus vector addition methods, and questions arise regarding the directionality of the vectors based on given magnitudes.
Discussion Status
Participants are exploring various methods to approach the problem, with some suggesting the use of trigonometric relationships while others express confusion about the lack of directional information for the vectors. There is no explicit consensus, but guidance has been offered regarding the nature of the triangle and the relationships between its angles.
Contextual Notes
Participants note that the problem provides limited information, specifically only the magnitudes of certain vectors and an angle, which raises questions about how to determine the orientation of the triangle formed by the vectors.
- #2
Dick
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Start with the first one. Draw the vectors head to tail so they make a triangle. The information they are giving you tells you some sides and angles in the triangle. Use trig.
- #3
Maximillien
- 8
- 0
Ya that's the part I don't know how to do
Because it # 11 it gives you Vector a = 5 cm long (the magnitude I believe) then it says C or the Resultant is also 5.0 cm long and the angle between A and C is 70 degrees I have no idea how to draw that. I'm used to going in the fashion of Vector A (polar or rectangular) + Vector B (polar or rectangular) + C (polar or rectangular) .. = Resultant
or using the unit vector notation... And for these problems would I have to use the laws of sine and cosine or could I just do it with a vector additon method.
Because it # 11 it gives you Vector a = 5 cm long (the magnitude I believe) then it says C or the Resultant is also 5.0 cm long and the angle between A and C is 70 degrees I have no idea how to draw that. I'm used to going in the fashion of Vector A (polar or rectangular) + Vector B (polar or rectangular) + C (polar or rectangular) .. = Resultant
or using the unit vector notation... And for these problems would I have to use the laws of sine and cosine or could I just do it with a vector additon method.
- #4
Dick
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Look at the second picture here. http://hyperphysics.phy-astr.gsu.edu/hbase/vect.html. Relabel R to C. That's the picture you should have. It's a triangle. Now fix the lengths and angles you match what you have. Looks to me like an isosceles triangle with side A=side C and an angle of 70 degrees between then. I would find the other angles just using that the sum of all of angle of a triangle is 180. Etc. Sure use things like the law of sines and law of cosines. You can't just directly use a vector addition method because you aren't given any components to add.
- #5
Maximillien
- 8
- 0
Ya I always draw triangles just like that
my problem is they only give the magnitude i believe for A and the magnitude for the resultant so how can I know in what direction the triangles should go ?
my problem is they only give the magnitude i believe for A and the magnitude for the resultant so how can I know in what direction the triangles should go ?
- #6
Dick
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Maximillien said:
You don't have to know that. They are only asking you for the magnitude of B and it's relative angles with the other vectors. You can't know anything about say, the orientation of the triangle. They don't give you enough information to determine that.
- #7
Maximillien
- 8
- 0
So would I use the same method to solve the other #'s ? Thanks a million Dick.
- #8
CompuChip
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Where did the first post go? It just shows dots now... 