SOLUTION: The cables supporting a straight line suspension bridge are nearly parabolic in shape. Suppose that a suspension bridge is being designed with concrete supports 200 feet apart and
Algebra ->
Test
-> Lessons
-> SOLUTION: The cables supporting a straight line suspension bridge are nearly parabolic in shape. Suppose that a suspension bridge is being designed with concrete supports 200 feet apart and
Log On
Question 862393: The cables supporting a straight line suspension bridge are nearly parabolic in shape. Suppose that a suspension bridge is being designed with concrete supports 200 feet apart and with vertical cables 30 ft above road level at the midpoint of the bridge and 80 ft above the road level at 30 ft from the midpoint of the bridge. How long are the longest vertical cables? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! The cables supporting a straight line suspension bridge are nearly parabolic in shape.
Suppose that a suspension bridge is being designed with concrete supports 200 feet apart and with vertical cables 30 ft above road level at the midpoint of the bridge and 80 ft above the road level at 30 ft from the midpoint of the bridge.
How long are the longest vertical cables?
:
Put the vertex on the y axis, vertex x=0 y=30
Using the form ax^2 + bx + c = y
Vertex is on the y axis so we can ignore b, c=30, find a
x=30, y=80
a(30^2) + 30 = 80
900a = 80 - 30
900a = 50
a = 50/900
a = .056
then y = .056x^2 + 30 is our equation, bridge goes from -100 to +100
looks like this
the longest vertical cable will be at x = +/-100
y = .056(100^2) + 30
y = 560 + 30
y = 580 ft, the green line
:
