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3 years ago

Please Helpp! The picture posted is the question I have . TIA

Mathematics

1 answer:

OleMash [197]3 years ago

4 0

The equation for volume of a sphere is:

Volume = 4/3 * PI * r^3

r is the radius = 1 inch

Volume is given as 4 cubic inches per second increase.

Given: dv/dt = 4 cubic inches per second.

Need to find dr/dt

Formula for volume of a sphere is: V = 4/3 * π * r^3

so now we have:

4 in^3 = 4 * π *1^2

Divide both sides by 4 * π *1^2

4 in^3 / 4π = 1/π inch per second.

The answer is 1/π inch per second ( exact answer)

or as a decimal: 0.3183 ( round as needed).

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Find the work (in ft-lb) required to pump all the water out of a cylinder that has a circular base of radius 7 ft and height 200

Virty [35]

Answer:

work done is equal to 384279168 lb-ft

Step-by-step explanation:

The cylinder has a circular base of 7 ft.

The height of the cylinder is 200 ft

The weight density of water in the cylinder is 62.4 lb/ft^3

First, we find the volume of the water in the cylinder by finding the volume of this cylinder occupied by the water.

The volume of a cylinder is given as $\pi r^{2} h$

where, r is the radius,

and h is the height of the cylinder.

the volume of the cylinder = $3.142* 7^{2}*200$ = 30791.6 ft^3

Since the weight density of water is 62.4 lb/ft^3, then, the weight of the water within the cylinder will be...

weight of water = 62.4 x 30791.6 = 1921395.84 lb

We know that the whole weight of the water will have to be pumped out over the height of cylindrical container. Also, we know that the work that will be done in moving this weight of water over this height will be the product of the weight of water, and the height over which it is pumped. Therefore...

The work done in pumping the water out of the container will be

==> (weight of water) x (height of cylinder) = 1921395.84 x 200

==> work done is equal to 384279168 lb-ft

7 0

3 years ago

baherus [9]

Answer: see proof below

Step-by-step explanation:

Given: cos 330 = $\frac{\sqrt3}{2}$

Use the Double-Angle Identity: cos 2A = 2 cos² A - 1

$\text{Scratchwork:}\quad \bigg(\dfrac{\sqrt3 + 2}{2\sqrt2}\bigg)^2 = \dfrac{2\sqrt3 + 4}{8}$

Proof LHS → RHS:

LHS cos 165

Double-Angle: cos (2 · 165) = 2 cos² 165 - 1

⇒ cos 330 = 2 cos² 165 - 1

⇒ 2 cos² 165 = cos 330 + 1

Given: $2 \cos^2 165 = \dfrac{\sqrt3}{2} + 1$

$\rightarrow 2 \cos^2 165 = \dfrac{\sqrt3}{2} + \dfrac{2}{2}$

Divide by 2: $\cos^2 165 = \dfrac{\sqrt3+2}{4}$

$\rightarrow \cos^2 165 = \bigg(\dfrac{2}{2}\bigg)\dfrac{\sqrt3+2}{4}$

$\rightarrow \cos^2 165 = \dfrac{2\sqrt3+4}{8}$

Square root: $\sqrt{\cos^2 165} = \sqrt{\dfrac{4+2\sqrt3}{8}}$

Scratchwork: $\cos^2 165 = \bigg(\dfrac{\sqrt3+1}{2\sqrt2}\bigg)^2$

$\rightarrow \cos 165 = \pm \dfrac{\sqrt3+1}{2\sqrt2}$

Since cos 165 is in the 2nd Quadrant, the sign is NEGATIVE

$\rightarrow \cos 165 = - \dfrac{\sqrt3+1}{2\sqrt2}$

LHS = RHS $\checkmark$

4 0

3 years ago

Simplify h(w)=6*2^(w-1) Answer: ㏒₂(hw/6)=w-1

Alex73 [517]

Answer: log₂ $(\frac{h(n)}{6})$ + 1 = n

Step-by-step explanation:

h(n) = 6 * 2ⁿ⁻¹

÷6 ÷6

$\frac{h(n)}{6}$ = 2ⁿ⁻¹

log₂ $(\frac{h(n)}{6})$ = log₂(2ⁿ⁻¹) →→log₂2 cancels out

log₂ $(\frac{h(n)}{6})$ = n - 1

log₂ $(\frac{h(n)}{6})+1$ = n

6 0

3 years ago

Sketch the quadratic function f(x) = -2x2 + 4x + 6. Which key feature of the graph is not true?

sertanlavr [38]

Answer:

D is false

Step-by-step explanation:

f(x) = -2x2 + 4x + 6 should be written with a " ^ " to indicate exponentiation:

f(x) = -2x^2 + 4x + 6.

Because of the - sign, we know that the graph of this function opens down, so there is a maximum at the vertex. We can determine the x-value at the vertex by using the formula x = -b/(2a), which here is x = -4/(2*-2), or 1.

Evaluating f(x) = -2x^2 + 4x + 6 at x = 1, we get -2 + 4 + 6, or 8. So statement A is true: there's a max at (1, 8). This is also the vertex of the graph.

Let's now look at C and D. We evaluate f(x) at x = 3 and x - 2. If the output (y) value is 0, we know we have an x - intercept:

f(3) = -2(9) + 4(3) + 6 = 0. Yes, C is true, (3, 0) is an x-intercept.

f(-2) = -2(4) - 8 + 6 is not 0. Therefore D is false; (-2, 0) is not an x-intercept.

Look at B: Let x = 0 and find y: it's 6. Thus, (0, 6) is the y-intercept. B is true.

4 0

3 years ago

Which of the following data sets represents a positive correlation?

Papessa [141]

The answer would be B, because it has a general upward slope

4 0

3 years ago

Read 2 more answers