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
grigory [225]
2 years ago
15

A rectangular field is to be enclosed on four sides with a fence. Fencing costs $2 per foot for two opposite sides, and $3 per f

oot for the other two sides. Find the dimensions of the field of area 830 ft2 that would be the cheapest to enclose.
Physics
1 answer:
borishaifa [10]2 years ago
8 0
<h2>Dimension for cheap enclose = 32.45 ft x 23.52 ft</h2>

Explanation:

Area of rectangular field, A = 830 ft²

Length = l

Width = w

So we have

                 l x w = 830

                    l=\frac{830}{w}

Fencing costs $2 per foot for two opposite sides, and $3 per foot for the other two sides.

            Cost for fencing, C = 2 x 2 x w + 3 x 2 x l = 4 w + 6 l

             C=4w+6\times \frac{830}{w}

For minimum cost we have derivative is zero

           dC=4\times dw-6\times \frac{830}{w^2}\times dw\\\\0=4\times dw-6\times \frac{830}{w^2}\times dw\\\\w^2=1245\\\\w=32.45ft\\\\lw=830\\\\l\times 32.45=830\\\\l=23.52ft

Dimension for cheap enclose = 32.45 ft x 23.52 ft

You might be interested in
Two identical stones are thrown from the top of a tall building. Stone 1 is thrown vertically downward with an initial speed v,
Molodets [167]

If the resistance of the Air is ignored, we can use the theory given by Galileo in which he warned that the thermal velocity of a body in free fall was given by

v= \frac{1}{2}gt

Where

g = Gravitational acceleration

t = time

As we can see the speed of objects in free fall is indifferent to the position that is launched (as long as the resistance of the air is ignored) or its mass.

Both bodies will end with the same thermal speed.

5 0
2 years ago
Could someone tell me if this is right or give me the answers so i can re write them! That would be so helpful:)
Ivahew [28]

Answer:

Those are all right

Explanation:

6 0
3 years ago
Read 2 more answers
Temperature and pressure of a region upstream of a shockwave are 295 K and 1.01* 109 N/m². Just downstream the shockwave, the te
seraphim [82]

Answer:

change in internal energy 3.62*10^5 J kg^{-1}

change in enthalapy  5.07*10^5 J kg^{-1}

change in entropy 382.79 J kg^{-1} K^{-1}

Explanation:

adiabatic constant \gamma =1.4

specific heat is given as =\frac{\gamma R}{\gamma -1}

gas constant =287 J⋅kg−1⋅K−1

Cp = \frac{1.4*287}{1.4-1} = 1004.5 Jkg^{-1} k^{-1}

specific heat at constant volume

Cv = \frac{R}{\gamma -1} = \frac{287}{1.4-1} = 717.5 Jkg^{-1} k^{-1}

change in internal energy = Cv(T_2 -T_1)

                            \Delta U = 717.5 (800-295)  = 3.62*10^5 J kg^{-1}

change in enthalapy \Delta H = Cp(T_2 -T_1)

                                 \Delta H = 1004.5*(800-295) = 5.07*10^5 J kg^{-1}

change in entropy

\Delta S =Cp ln(\frac{T_2}{T_1}) -R*ln(\frac{P_2}{P_1})

\Delta S =1004.5 ln(\frac{800}{295}) -287*ln(\frac{8.74*10^5}{1.01*10^5})

\Delta S = 382.79 J kg^{-1} K^{-1}

7 0
2 years ago
(b) A piece of wood of volume 0.6 m² floats in water. Find the volume
enot [183]

Answer:

Explanation:

Let the volume below water be v . Then

buoyant force = v d g where d is density of water , g is acceleration due to gravity

= v x 1000 x g

weight of wood piece = volume x density of wood x g

= .6 x 600 x g

for equilibrium while floating

buoyant force = weight

= v x 1000 x g  =  .6 x 600 x g

v = .36 m²

volume above water or volume exposed = .6 - .36

= .24 m²

When immersed completely ,

buoyant force = .6 x 1000 x 9.8

= 5880 N

weight of wood

=  .6 x 600 x g

= 3528 N

buoyant force is more than the weight . In order to equalise them for floating with full volume in water

weight required = 5880 - 3528

= 2352 N.

6 0
3 years ago
What would happen if you tried to use a prism to disperse a beam that contained only green light?​
Margaret [11]

It is determined by the nature of the green light. Because lasers create light at almost a single frequency, green laser light would appear as a thin line of pure green. Other sources of "green" light emit light at a variety of frequencies, including yellow and blue, resulting in a strong green band in the center that fades into blue-green and yellow-green at the borders.

For example, here’s a graph of the spectrum of a green LED, showing the color range: Attachment #1

and here’s a graph of the transmission spectra of several standard photographic filters, including green: Attachment #2

Learn more about the color spectrum:

  • brainly.com/question/14552374
  • brainly.com/question/20930002

#SPJ2

4 0
1 year ago
Other questions:
  • What is the proper battery cable connection when jumping two automotive batteries? (a) negative to negative / positive to positi
    9·1 answer
  • What are the limitations of using solar panels?
    5·1 answer
  • To properly operate the laboratory thermometer Group of answer choices it needs to be shaken but make sure you have enough room
    7·1 answer
  • A spherical capacitor contains a charge of 3.50 nC when connected to a potential difference of 210.0 V. Its plates are separated
    11·1 answer
  • The dean of a university located near the ocean (who was not a science major in college) proposes building an infrared telescope
    10·1 answer
  • What is the magnitude (in N/C) and direction of an electric field that exerts a 3.50 ✕ 10−5 N upward force on a −1.55 µC charge?
    15·1 answer
  • 1,What were you doing when you felt most passionate and alive?
    15·2 answers
  • What is inertia? (1 point)
    10·1 answer
  • Energy that is transferred from a warmer object to a cooler object is called
    6·2 answers
  • Without friction, what is the mass of an ball accelerating at 1.8 m/sec2 to which an
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!