Question

a cable suspended from supports that are 600 ft apart and on the same height has a sag of 100 ft, if the cable hangs in the form of a parabola. Find its eqaution, taking the origin at the lowest level

Answer 1

Answer:

Let the equation of the parabola be x2=4ay by taking lowest point as the origin & vertical line through it as y-axis.

Now, the points of both the supports will be at (−300,100) & (300,100) which lie on the parabola hence, setting x=300 & y=100 in the equation we get

(300)2=4a(100)

4a=90000100=900

Hence, setting the value of 4a, the equation of the parabola is

x2=900y