4. To hold up a communications tower which is 100 m high, 3 sets of 2 cables (as shown in the diagram) are positioned equally around the tower. Find the total length of cable required if an extra 4 m are needed to fasten each wire.

4 To hold up a communications tower which is 100 m high 3 sets of 2 cables as shown in the diagram are positioned equally around the tower Find the total length class=

Respuesta :

[tex]\text{total length=}572.62\text{ m}[/tex]

Explanation

Step 1

a) the wire at 65 ° ( red)

we have a rigth triangle (B) so

let

length of the wire= hypotenuse

angle=65 °

opposite side= 100

hence, we need use a funciton that relates those three values

[tex]\sin \theta=\frac{opposite\text{ side}}{\text{hypotenuse}}[/tex]

replace

[tex]\begin{gathered} \sin \theta=\frac{opposite\text{ side}}{\text{hypotenuse}} \\ \sin 65=\frac{100}{\text{wire}1} \\ \text{wire}1=\frac{100}{\sin 65} \\ \text{wire}1=110.33 \end{gathered}[/tex]

Step 2

now, let's find the distnace x

[tex]\begin{gathered} \cos \theta=\frac{adjacent\text{ side}}{\text{hypotenuse}} \\ \text{hyp}\cdot\cos \theta=x \\ \text{replace} \\ 110.33\cdot\cos 65=x \\ 46.63=x \end{gathered}[/tex]

Step 3

now, find wire 2

[tex]\begin{gathered} \text{wire}2\cdot\cos 50=x \\ \text{wire}2=\frac{x}{\cos 50} \\ \text{wire}2=\frac{46.63}{\cos 50} \\ \text{wire}2=72.54 \end{gathered}[/tex]

Step 4

finally, to find the total length of the wire

, add

total length= (wire1+wire2+4+4)*3times

replace

[tex]\begin{gathered} \text{total length= (110.33+72.54+8)}\cdot3 \\ \text{total length=}572.62\text{ m} \end{gathered}[/tex]

therefore, the answer is

[tex]\text{total length=}572.62\text{ m}[/tex]

I hope this helps you

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