Can I find the distance from Ax to C in this problem?

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Homework Help Overview

The discussion revolves around determining the distance from point Ax to point C in a problem involving beams and joints. The context includes a triangle formed by points A, B, and C, with specific forces applied.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants explore whether sufficient information is available to find the distance from Ax to C, considering the geometry of triangle ABC. Questions about calculating angles and using perpendiculars to find lengths are raised.

Discussion Status

Some participants suggest that sufficient information exists to determine the necessary distances, while others are exploring the implications of triangle properties and relationships. There is an acknowledgment of the need to calculate specific angles to proceed.

Contextual Notes

Participants note the constraints of the problem, including the weightless nature of the beams and the connections at the joints. There is also a mention of the original poster's uncertainty regarding the information available for solving the problem.

Femme_physics
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Homework Statement


I'm not sure if I have enough information. I solved for Ay and By. But do I have the distance from Ax to C when I isolate the beam AD?

http://img191.imageshack.us/img191/7963/20092009.jpg


P = 5 [kN]
Beams are weightless and connected by joints


The Attempt at a Solution



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Femme_physics said:
I'm not sure if I have enough information. I solved for Ay and By. But do I have the distance from Ax to C when I isolate the beam AD?

You do have enough information.
Of the triangle ABC you have 2 sides and 1 angle.
That is enough to completely determine ABC and anything related.

Can you calculate the angle between AB and AC?

Suppose you draw a line from C to a point on AB that is perpendicular.
Let's call this point E.
Can you calculate the length of CE now (using the angle)?
 
I like Serena is completely correct. More generally any time you drop a perpendicular from the right angle of a right triangle to the hypotenuse, you divide the triangle into two right triangles, both similar to the original triangle. If you are very clever, you don't need to calculate the angle at all or use any trig functions- however, you may find it simplest to use the cosine of A.
 
Good call, I need to find angle BAC first. I needed to think more instead of going to the league of genius (i.e. you) at the first sign of desperation. My gratitude :)
 

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