A sign with a mass of 13kg is suspended above a sidewalk by two wires. If each wire can sustain a maximum tension of 119.5Newtons, what is the smallest angle the sign can be hung at?

1 Answer
Oct 28, 2015

Here,
The weight of the sign is 13* 9.81 = 127.5N

So here you can see that the sign is being pulled by gravity with a force of 127.5N. and in order to make the sign stable, the wires must pull the sign with the same force.

Upward force = Downward force, as it is in equilibrium,

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Now the force exerted by the strings vertically is 119.5 sin Q *2

SO

119.5*2 sinQ = 127.5
sinQ = 0.533
So, Q= 32.2 degrees

So the wires must be aligned 32.2 degrees above the horizon.