Solving the systems of equations by elimination-solo team teach x+y=-7 3x+y=-9

A sphere and a cylinder have the same radius and height. The volume of the cylinder is 21m. what is the volume of the sphere.

Goshia [24]

Answer:

The volume of the sphere is 14m³

Step-by-step explanation:

Given

Volume of the cylinder = $21m^3$

Required

Volume of the sphere

Given that the volume of the cylinder is 21, the first step is to solve for the radius of the cylinder;

Using the volume formula of a cylinder

The formula goes thus

$V = \pi r^2h$

Substitute 21 for V; this gives

$21 = \pi r^2h$

Divide both sides by h

$\frac{21}{h} = \frac{\pi r^2h}{h}$

$\frac{21}{h} = \pi r^2$

The next step is to solve for the volume of the sphere using the following formula;

$V = \frac{4}{3}\pi r^3$

Divide both sides by r

$\frac{V}{r} = \frac{4}{3r}\pi r^3$

Expand Expression

$\frac{V}{r} = \frac{4}{3}\pi r^2$

Substitute $\frac{21}{h} = \pi r^2$

$\frac{V}{r} = \frac{4}{3} * \frac{21}{h}$

$\frac{V}{r} = \frac{84}{3h}$

$\frac{V}{r} = \frac{28}{h}$

Multiply both sided by r

$r * \frac{V}{r} = \frac{28}{h} * r$

$V = \frac{28r}{h}$ ------ equation 1

From the question, we were given that the height of the cylinder and the sphere have equal value;

This implies that the height of the cylinder equals the diameter of the sphere. In other words

$h = D$ , where D represents diameter of the sphere

Recall that $D = 2r$

So, $h = D = 2r$

$h = 2r$

Substitute 2r for h in equation 1

$V = \frac{28r}{2r}$

$V = \frac{28}{2}$

$V = 14$

Hence, the volume of the sphere is 14m³

4 0

3 years ago

Read 2 more answers

DUPLICATE. WITH ATTACHMENTS

Inessa05 [86]

7.) Area of a square pyramid is given by A = s^2 + 2sl; where s is the side length of the base and l is the slant height.
Area of given pyramid = 4^2 + (2 x 4 x 7) = 16 + 56 = 72 ft^2

8.) Area of the given pyramid is the area of the hexagonal base plus the area of the six slant triangles.
Area of hexagonal base = (3sqrt(3))/2 x 10^2 = 150 x 1.732 = 259.8
Area of the 6 traingles = 6(1/2 x 10 x 13) = 6 x 65 = 390
Total surface area of the pyramid = 259.8 + 390 = 649.8 ≈ 650 m^2

9.) Using pythagoras rule, the slant height is sqrt(6^2 + 3.5^2) = sqrt(36 + 12.25) = sqrt(48.25) = 6.9 mm

10.) The surface area of a cone is given by πr^2 + πrl
Area = π x 6^2 + π x 6 x 20 = 36π + 120π = 490.1 cm^2

11.) l = sqrt(r^2 + h^2) = sqrt(11^2 + 16^2) = sqrt(121 + 256) = sqrt(377) = 19m

6 0

3 years ago

Can someone pls help me Pls

lora16 [44]

Answer:

help u with what? Say what u need

5 0

3 years ago

In the typing World 120 words in 3 minutes is average how many words could they type in 2 hours

Molodets [167]

Answer:

7,200 words