An arch is in the form of a parabola


Asked by admin @ in Math viewed by 124 People


Question 2 An arch is in the form of a parabola with its axis vertical. The arch is 10 m high and 5 m wide at the base. How wide is it 2 m from the vertex of the parabola?

Class X1 - Maths -Conic Sections Page 264

Answered by admin @



See attachment, axis is vertical , so let arc of parabola is in the form of x² = 4ay
here, OB = 10 m
AC = 5 m so, AB = BC = 5/2 = 2.5 m
so, the co-ordinate of A = ( 2.5 , 10)
point A ( 2.5, 10) will satisfy equation of parabola .
so,
( 2.5)² = 4 × a × 10
6.25 = 40a
a = 6.25/40 = 5/32
now, equation of parabola is x² = 4 × 5/32y
x² = 5y/8 __________(1)

Let OR = 2 m and PQ = k then, RP = k/2
hence, point P( k/2, 2) .
point P will also satisfy equation of parabola .
put P ( k/2, 2) in equation (1)
(k/2)² = 5 × 2/8
k²/4 = 5/4
k = ±√5 but k is distance so, K won't be negative.
k = √5 .

hence, √5 m wide it is 2m from the vertex of the parabola.

Similar Questions

How to find a in standard form of a parabola

Asked by admin @ in Mathematics viewed by 257 persons

Find the standard form of the equation of the parabola with a vertex at the origin and a focus at (0, -4).

What is the equation in standard form of a parabola that models the values in the table

Asked by maham237 @ in Mathematics viewed by 288 persons

x -1 0 2 f(x) 10 5 13 a. y = 3x^2 - 2x + 5 b. y = x^2 - 2x + 5 c. y = 2x^2 - 3x …

Graphing a parabola of the form y xh 2 k

Asked by admin @ in Mathematics viewed by 238 persons

If the parabola of the form y = a(x – h)2 + k is always shifted horizontally h units and vertically k units, then its vertex is always

Overcoming fixed mindset: a step-by-step guide to cultivating a growth mindset

Asked by wiki @ in Health viewed by 1213 persons

Which of the following would best complete this list?

Asked by wiki @ in Social Studies viewed by 692 persons

What had the king decided to do before he saw the spider

Asked by vanshika149 @ in English viewed by 1076 persons

Describe the karez in your own words

Asked by rajesh064 @ in English viewed by 1232 persons

What is 8 + (x + 5)?

Asked by jaylord7 @ in Mathematics viewed by 1033 persons

What is the topic of the info grapher

Asked by jesus643 @ in History viewed by 1326 persons

Elephant kills 11 in nepal , woman rescued from a friendly dolphine

Asked by kavin044 @ in English viewed by 1201 persons

(-3,0);slope =2/3

Asked by timothy2 @ in Biology viewed by 1475 persons

Which is an example of situational irony in "wherefore art thou romeo?”

Asked by noah5213 @ in English viewed by 1494 persons

Most viewed questions in Math


What is the value of x in the expression

Asked by admin @ in Math viewed by 15115 persons


Shubham is facing south and moves 30 km

Asked by admin @ in Math viewed by 12972 persons


Prachi excellence in mathematics class 7 solutions pdf free download

Asked by admin @ in Math viewed by 12015 persons



Oxford new enjoying mathematics class 7 solutions chapter 1

Asked by admin @ in Math viewed by 11502 persons


Survey of various types of bank accounts icse project

Asked by admin @ in Math viewed by 11501 persons


The town of p is located at point x

Asked by admin @ in Math viewed by 11352 persons



A clock gains 4 minutes after every 4 minutes

Asked by admin @ in Math viewed by 10160 persons


Running a tuck shop or canteen maths project pdf

Asked by admin @ in Math viewed by 9371 persons


Paul is sixteenth from the front of the row

Asked by admin @ in Math viewed by 9343 persons



The average weight of 20 teachers is 80 kg

Asked by admin @ in Math viewed by 7514 persons


The number 567 xy is completely divisible by 30

Asked by admin @ in Math viewed by 7392 persons


In a row of friends tiya occupies fifteenth place

Asked by admin @ in Math viewed by 7200 persons



What would $ mean if fat is coded as

Asked by admin @ in Math viewed by 5267 persons


Consider a 3 digit integer x with distinct digits

Asked by admin @ in Math viewed by 4796 persons


Rahul went to his mother's mother in law

Asked by admin @ in Math viewed by 4173 persons