contestada

9 b. A sign (including the post and base) weighs 40 pounds and is
supported by an 18 in. x 18 in. square base, as shown in the illustration
below.
• If the wind applies a force of 13.2 lb to the sign at the geometric center
of the sign surface, will the sign tip over? YES
• If so, how much evenly distributed weight (sand bags) should be
added to the base of the sign to keep it from tipping when the wind
blows? (precision of 0.0 lb)

Respuesta :

Answer:

The weight should be added to the base of the sign to keep it from tipping is 65.6 lb

Explanation:

Given data:

A sigh weighs 40 pounds

Suported by an 18 in x 18 in square

Force of the wind 13.2 lb

Questions: Will the sign tip over, if yes, how much evelnly distributed weight should be added to the base of the sign to keep it from tipping, W = ?

The sign and the post have a length of 6 ft. You need to calculate the distance from the edge to the middle point:

18/2 = 9 in = 0.75 ft

Force acting in the base (40 lb):

[tex]F=\frac{40*0.75}{6} =5lb[/tex]

The weight should be added to the base:

[tex](40+W)*\frac{0.75}{6} =13.2\\W=65.6lb[/tex]

Otras preguntas