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Naddika [18.5K]

3 years ago

7

A plane intersecting a double-napped cone is perpendicular to the central axis. Which conic section is formed?

2 answers:

kkurt [141]3 years ago

7 0

A) Circle

Correct on Edge 2021

Vitek1552 [10]3 years ago

7 0

Answer:

A

Step-by-step explanation:

Edge 2021

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What is an atom? GIVING BRAINLIEST 30 POINTS PLEASE HELP

miskamm [114]

1. Option 4
2. Option 2
3. Option 2
4. Option 4 (not completely sure)
5. Option 2
6. Option 1 (not completely sure)
7. Option 4
8. <span>Isotopes are caused by different numbers of neutrons in the electron cloud
9. Not sure of the question
10. Positive charge
11. nucleus
</span>

8 0

3 years ago

The surface area of a cylinder is increasing at a rate of 9 pi square meters per hour. The height of the cylinder is fixed at 3

Alekssandra [29.7K]

Answer:

$9\pi \text{ cubic meters per hour}$

Step-by-step explanation:

Since, the surface area of a cylinder,

$A= 2\pi r^2 + 2\pi rh$ ................(1)

Where,

r = radius,

h = height,

If $A= 36\pi\text{ square meters}, h = 3\text{ meters}$

$36\pi = 2\pi r^2 + 2\pi r(3)$

$18 = r^2 + 3r$

$\implies r^2 + 3r - 18=0$

$r^2 + 6r - 3r - 18 = 0$ ( by middle term splitting )

$r(r+6)-3(r+6)=0$

$(r-3)(r+6)=0$

By zero product property,

r = 3 or r = - 6 ( not possible )

Thus, radius, r = 3 meters,

Now, differentiating equation (1) with respect to t ( time ),

$\frac{dA}{dt}= 4\pi r\frac{dr}{dt} +2\pi(r\frac{dh}{dt} + h\frac{dr}{dt})$

∵ h = constant, ⇒ dh/dt = 0,

$\frac{dA}{dt} = 4\pi r \frac{dr}{dt} +2\pi h \frac{dr}{dt}$

We have, $\frac{dA}{dt}=9\pi\text{ square meters per hour}, r = h = 3\text{ meters}$

$9\pi = 4\pi (3) \frac{dr}{dt}+2\pi (3)\frac{dr}{dt}$

$9\pi = (12\pi + 6\pi )\frac{dr}{dt}$

$9\pi = 18\pi \frac{dr}{dt}$

$\implies \frac{dr}{dt} =\frac{1}{2}\text{ meter per hour}$

Now,

Volume of a cylinder,

$V=\pi r^2 h$

Differentiating w. r. t. t,

$\frac{dV}{dt}=\pi ( r^2 \frac{dh}{dt}+h(2r)\frac{dr}{dt})=\pi ((3)(6) (\frac{1}{2})) = 9\pi \text{ cubic meters per hour}$

6 0

3 years ago

What is the perimeter of a rectangle that

expeople1 [14]

Answer:

<h2>The answer is option C</h2>

Step-by-step explanation:

Perimeter of a rectangle = 2l + 2w

where

l is the length

w is the width

From the question

l = 9 cm

w = 6 cm

Substitute the values into the above formula and solve

We have

P = 2(9) + 2(6)

= 18 + 12

We have the final answer as

<h3>P = 30 cm</h3>

Hope this helps you

6 0

3 years ago

Read 2 more answers

Choose all answers that apply:<br> a - -1.5 < x < -0.5<br> b- 0 c- 3.5 d- none of the above

Darya [45]

Answer:

None of the above.

Step-by-step explanation:

The interval where h is increasing is -1.5 < x < 1.5. Answers a, b, and c do not match.

3 0

3 years ago

2. Convert 3.554 into a percent.

irina1246 [14]

Answer:

355.4%

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers