Did I Solve the Vertical Post Problem Correctly Using SOH CAH TOA?

[Ryan Lau]

Homework Statement

A vertical post is held in place by two cables as shown.

Homework Equations

SOH CAH TOA

The Attempt at a Solution

http://postimg.org/image/6rgssb1j5/

The answer in the textbook is 63 degrees. Is this an issue or did I do something terribly wrong?

 

[ehild]

The tension in the cables keep the post in vertical position. Its top point can not move sideways, the horizontal components of the tensions balance each other.
The vertical components do not need to be equal, as they are balanced by the force from the ground.

 

[Ryan Lau]

The tension in the cables keep the post in vertical position. Its top point can not move sideways, the horizontal components of the tensions balance each other.
The vertical components do not need to be equal, as they are balanced by the force from the ground.

Unfortunately, I do not fully comprehend this explanation. My question is why 33 degrees is not the correct angle for Theta.

 

[ehild]

Unfortunately, I do not fully comprehend this explanation. My question is why 33 degrees is not the correct angle for Theta.

You calculated theta from the condition that the vertical components of the tensions are equal, which is wrong .

 

[Ryan Lau]

You calculated theta from the condition that the vertical components of the tensions are equal, which is wrong .

I believe I understand this comment now.

Overview:
To keep the vertical post upright, both the left and right side of the ground by the tensional strings will be equal to each other.

1500cos50 = 964.1814 N = Adjacent Side (floor)
Cos Inv. (964.1814/2100) = 62.6688 N (angle required to keep the pole upright)

 

[ehild]

And the rounded value is 63°.