Question

A wireless aerial attached to the top of a mast 20 m high exerts a horizontal force upon it of 600 N. The mast is supported by a stay-wire running to the ground from a poult 6 m below the top of the mast. and inclined at 600 to the horizontal. Assuming that the action of the ground on the mast can be regarded as a single force. draw a diagram of the forces acting on the mast, and determine by measurement or by calculation the force in the stay-wire. (C.)

Answer 1

Given,

Horizontal force $F_H=600N$

Let the force in the wire be $T$

Angle made with horizontal $\theta=60^{\circ}$

then for Equllibrium

$\sum F=0$

$\Rightarrow Tcos60^{\circ}=600\\\Rightarrow T\times \dfrac{1}{2}=600\\\Rightarrow T=1200N$

Hence the force in the stay wire is $1200N$ .