What is the expression of (0.2)(14)

a pyramid whose altitude is 5ft weighs 800lbs. at what distance from its vertex must it be cut by a plane parallel to its base s

slavikrds [6]

A structure which has a square base and four triangular sides meeting at a point is called pyramid.

At distance of 3.97 feet from its vertex , pyramid is cut by plane so that the two solids of equal weight will be formed.

It is assumed that weight of pyramid is proportional to its volume.

So, $w = k V$ , where V is volume of original pyramid and v is volume of small pyramid and k is constant.

Let us consider that at h distance, pyramid is cut from its vertex. So a small pyramid is also formed.

Assume that base area of original pyramid is A and base of small pyramid is a.

Volume of original pyramid is, $V= \frac{1}{3} *A* 5$

So, weight of original pyramid, $W = k *(\frac{1}{3} *A* 5) = 800$

Volume of small pyramid is, $v = \frac{1}{3}* a* h$

So, weight of small pyramid, $w = k*(\frac{1}{3}* a* h)=400$

Since, base and height of small pyramid and original pyramid are in proportion.

So, $\frac{a}{A} = (\frac{h}{5}) ^{2}$

$a = (\frac{h}{5} )^{2}A$

Substituting value of a in equation $k*(\frac{1}{3}* a* h)=400$

So, $k*(\frac{1}{3}* \frac{h^{2} }{25}A * h)=400$

$(k*\frac{1}{3}* A*5)*\frac{1}{5} *\frac{h^{2} }{25} * h)=400$

Since, $(k *\frac{1}{3} *A* 5) = 800$ , substitute in above equation.

So, $800*\frac{h^{3} }{125}=400\\\\h^{3}=\frac{125}{2}\\\\h=\sqrt[\frac{1}{3} ]{62.5}\\\\h=3.97 feet$

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6 0

2 years ago

Read 2 more answers

PLS HELP PLS brain if correct 100 points!,

Cloud [144]

Answer:

The first and last one.

Step-by-step explanation:

you can't see over him

she is the same age

5 0

2 years ago

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For the following demand equation compute the elasticity of demand and determine whether the demand is elastic, unitary, or inel

adelina 88 [10]

Answer:

Demand is inelastic at p = 9 and therefore revenue will increase with

an increase in price.

Step-by-step explanation:

Given a demand function that gives q in terms of p, the elasticity of demand is

$E=|\frac{p}{q}\cdot \frac{dq}{dp} |$

If E < 1, we say demand is inelastic. In this case, raising prices increases revenue.
If E > 1, we say demand is elastic. In this case, raising prices decreases revenue.
If E = 1, we say demand is unitary.

We have the following demand equation $D(p)=-\frac{3}{4}p+29$ ; p = 9

Applying the above definition of elasticity of demand we get:

$E(p)=\frac{p}{q}\cdot \frac{dq}{dp}$

where

p = 9
q = $-\frac{3}{4}p+29$
$\frac{dq}{dp}=\frac{d}{dp}(-\frac{3}{4}p+29)$

$\frac{d}{dp}\left(-\frac{3}{4}p+29\right)=-\frac{d}{dp}\left(\frac{3}{4}p\right)+\frac{d}{dp}\left(29\right)\\\\\frac{d}{dp}\left(-\frac{3}{4}p+29\right)=-\frac{3}{4}$

Substituting the values

$E(9)=\frac{9}{-\frac{3}{4}(9)+29}\cdot -\frac{3}{4}\\\\E(9)=\frac{36}{89}\cdot -\frac{3}{4}\\\\E(9)=-\frac{27}{89}\approx -0.30337$

$|E(9)|=|\frac{27}{89}| < 1$

Demand is inelastic at p = 9 and therefore revenue will increase with an increase in price.

6 0

3 years ago

Melissa picked 4 times as many green peppers as red peppers. If she picked a total of 20 peppers, how many green peppers did she

Harman [31]

16, 4x4 = 16 that's your 4x as many as red peppers and the red peppers is therefore 4 and 16+4 is an even 20

3 0

3 years ago

Krystal and Danielle each improved their yards by planting daylilies and ivy. They bought their supplies from the same store. Kr

Eddi Din [679]

Answer:

$9 and $6

Step-by-step explanation:

Let the cost of daylilies = d and ivy = i, then we have below equations:

d + 12i = 114
10d + 10i = 150

Simplify the second equation:

d + i = 15

Subtract the second equation from the first:

d - d + 12i - i = 114 - 15
11i = 99
i = 9, ivy costs $9

Now find d:

d = 15 - 9 = 6, daylilies cost $6

6 0

3 years ago