1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Radda [10]
3 years ago
15

Semielliptical Arch Bridge An arch for a bridge over a highway is in the form of half an ellipse. The top of the arch is 20 feet

above the ground level (the major axis). The highway has four lanes, each 12 feet wide; a center safety strip 8 feet wide; and two side strips, each 4 feet wide. What should the span of the bridge be (the length of its major axis) if the height 28 feet from the center is to be 13 feet
Mathematics
1 answer:
photoshop1234 [79]3 years ago
7 0

Answer:

the span of the bridge is 73.7 feet

Step-by-step explanation:

The equation of an ellipse with a vertical major axis(i.e major axis parallel to y axis) is given by:

\frac{(x-h)^{2} }{b^{2} } + \frac{(y-k)^{2} }{a^{2} }= 1 a>b

where (h,k) are the coordinates of the center of the ellipse, a is the length of the major axis and b is the length of the minor axis

For this problem, the center of the ellipse (h,k) = (0,0)

Therefore:

\frac{(x)^{2} }{b^{2} } + \frac{(y)^{2} }{a^{2} }= 1

The top of the arch is 20 feet above the ground level (the major axis), therefore a=20

length of the major axis = 2a= 2*20 = 40

\frac{x^{2} }{b^{2} } + \frac{y^{2} }{20^{2} }= 1\\\frac{x^{2} }{b^{2} } + \frac{y^{2} }{400 }= 1

The coordinates of the ellipse (x,y) = (28,13)

\frac{28^{2} }{b^{2} } + \frac{13^{2} }{400 }= 1

\frac{28^{2} }{b^{2} } + 0.4225= 1

\frac{784 }{b^{2} } = 0.5775

b² ≅ 1358

b≅36.85

Length of minor axis (2b) = 73.7 feet.

the span of the bridge is 73.7 feet

You might be interested in
What is the radius of this circle?
dezoksy [38]

Answer: 6 cm

Step-by-step explanation:

6 cm is the radius because half the diameter is the radius

5 0
2 years ago
Read 2 more answers
Would really appreciate it... will mark brainliest
d1i1m1o1n [39]

Exponential growth would include, A = 20,000(1.08)^t, A=40(30), P=1700(1.07).

Decay would include, A=80(1/2)^t, A= 1600(.8), P=1700(.93)

Hope this helps.

5 0
3 years ago
Read 2 more answers
PLZ HELP PLZ HELP
ankoles [38]

Answer:

c

Step-by-step explanation:

3 0
2 years ago
how many different license plates can be formed if each plate plate has 5 different digits followed by 1 letter
Elina [12.6K]

This is a fundamental counting principle problem and can be solved by multiplying the number of choices you have for each digit of the license plate.

For the first five digits you can choose from the numbers 0,1,2...,9 or 10 choices.

A we cannot repeat the digits, so, first five digits will be:

10 × 9 × 8 × 7 × 6

Now the next 1 digit will all be letter all being different

There are 26 letters in the alphabet.. for our second digit we have 26 choices,

Here is the whole calculation:

= 10 × 9 × 8 × 7 × 6 × 26

= 786240

To learn more about calculating possibilities from the given link

brainly.com/question/4658834

#SPJ4

3 0
1 year ago
5 to the power of two
Maksim231197 [3]

Answer:

25

Step-by-step explanation:

5^2 = 25

5 * 5 = 25

6 0
3 years ago
Read 2 more answers
Other questions:
  • Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    15·1 answer
  • Find the Greatest Common Factor
    8·1 answer
  • Someone please please help<br> Meeeeeee
    13·1 answer
  • Please help me ..<br>Use the distributive property to factor the expression.<br>2k + 10<br>​
    14·1 answer
  • Next week your math teacher is giving a chapter test. The test will consist of 35 questions. some problems r worth 2 point and s
    5·2 answers
  • Nora loves chocolate. She was given 25 chocolate chips by her parents. She gave 5 to her sister and 10 to her brother. How many
    9·2 answers
  • Answer question 2 please
    6·1 answer
  • Someone help me pls!!
    13·1 answer
  • Find the arc length
    5·1 answer
  • the world's largest Apple had a mass of 1849 grams sue said the mass was greater than 2 kilogram does she stament make sense plz
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!