







A suspension bridge 
20160818 

From sai: The main cable of a suspension bridge has the shape of a parabola. The cables are strung from the top of two towers, 61 metres apart, each 15.25 metres high above the roadway. The cable is 1.5 metres above the roadway at the point that is directly between the towers.
h(x)=a(x30.5)^2+1.5
where a is the constant and its value to be determined.
a) determine the value of the constant a by using that the fact that height of the suspension cable, h(x) is 15.25 metres at each tower. Hence, write the updated model equation. Answered by Penny Nom. 





A parabolic suspension bridge 
20140311 

From jeffrey: the towers of a parabolic suspension bridges 200 meter long are 40 meter high and the lowest point of the cable is 10 meter above the roadway.Find the vertical distance from the roadway to the cable at 50 meter from the center. Answered by Penny Nom. 





A suspension bridge 
20111130 

From jennifer: suspension bridges like the golden gate bridge, are used to span large distances.
when the main curved cables are attached to the deck by vertical cables they will end
up in the shape of parabola. assume that we need to build a bridge that spans
2,400 feet. the two towers 165feet tall each where placed at 400feet from either
side. the lowest point of the center of the bridge at 10feet. vertical suspension cables
where placed at 25foot interval. how many feet of cable are needed to connect
the deck to the main cables between the two towers? show all working. Answered by Penny Nom. 





The capilano suspension bridge 
20100603 

From nida: the capilano suspension bridge in north vancouver is the world's highest footbridge of its kind. the bridge is 140m long . from the ends of the bridge the angles of depression of a point on the river under the bridge are 41 degrees and 48 degrees. how high is the bridge above the river to the nearest metre Answered by Penny Nom. 





What is so important about quadratics? 
20081129 

From zoe: what is so important about quadratics? Answered by Harley Weston. 





Parabolic suspension bridge 
20071009 

From Jessica: A suspesion bridge with weight uniformly distributed along its length has twin towers
that extend 75 meters abouve the road surfce and are 400 meters apart.The cables are
parabolic in shape and are suspended from the tops of the towers. The cables touch the road
surface at the center of the bridge. Find the height of the cables at a point
100 meters from the center. (Assume that the road is level.) Answered by Stephen La Rocque. 





A suspension bridge 
20010324 

From Janna: The cables of a suspension bridge hang in a curve which approximates a parabola. The road bed passed through the vertex. If the supporting towers are 720m apart and 60m high, find: a) an equation of the parabola (it's y = ^{1}/_{2160}x^{2}) b)the height of the cables at a point 30m from the vertex. I substituted 30 in for the x value and got 0.42 and the answer is 42. What did I do wrong? Answered by Denis Hanson and Claude Tardif. 

