Question

The tower of a bridge, hung in the form of
a parabola have their tops 30 meters above
the road way and are 200 meters apart. If the
cable is 5meters above the road way at the
centre of the bridge, find the length of the
vertical supporting cable from the centre.
​

Answer 1

The length of vertical cube is 29 / 4.

Step-by-step explanation:

Let us assume that lowest point of cable as origin and equation of parabola will be x^2  = 4 a.y  

Given, tower of bridge is 30 meters above the road-way and lowest point is 5 meters above the road.

Then in equation y-coordinate of top of tower is 25 meters and x-coordinate is 100 meters.

From equation we get 100^2   = 4 a(25) ⟹ a = 100

Now,length of the vertical supporting cable 30 metres from the centre is given by y+5 where y is given by 30^2  = 4 (100) (y)

⟹ y =   9/4

Then vertical length of cable is 5 +  9 / 4   =   29  / 4

Answer 2

Answer:

The length of vertical cube is 29 / 4.

Step-by-step explanation:

Let us assume that lowest point of cable as origin and equation of parabola will be x^2  = 4 a.y  

Given, tower of bridge is 30 meters above the road-way and lowest point is 5 meters above the road.

Then in equation y-coordinate of top of tower is 25 meters and x-coordinate is 100 meters.

From equation we get 100^2   = 4 a(25) ⟹ a = 100

Now,length of the vertical supporting cable 30 metres from the centre is given by y+5 where y is given by 30^2  = 4 (100) (y)

⟹ y =   9/4

Then vertical length of cable is 5 +  9 / 4   =   29  / 4

Step-by-step explanation:

Hope this answer will help you.✌️