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3 years ago

What is the surface area of the sphere below?

Mathematics

1 answer:

tatiyna3 years ago

3 0

Hey there! I'm happy to help!

To find the surface area of a sphere, here is what you do.

You square the radius.

4²=16

You multiply by 4.

16×4=64

And you multiply by pi!

64×π=64π

Therefore, the surface area of the sphere is A. 64π units². It's that easy!

Now you can find the surface area of a sphere! Have a wonderful day! :D

You might be interested in

The ratio of the surface areas of two similar solids is 4:49. What is the ratio of a volumes?

Fynjy0 [20]

Answer: 8/343

Step-by-Step:

If two similar solids have a scale factor of a:b then,

The ratio of their surface areas (2D) is- a^2:b^2

The ratio of their volume (3D) is- a^3:b^3

First you want to square root the scale factor numbers to find the original value. Then you cube the original numbers to find the answer.

6 0

3 years ago

A soup can in the shape of a right circular cylinder is to be made from two materials. The material for the side of the can cost

Advocard [28]

Answer:

Radius = 1.12 inches and Height = 4.06 inches

Step-by-step explanation:

A soup can is in the shape of a right circular cylinder.

Let the radius of the can is 'r' and height of the can is 'h'.

It has been given that the can is made up of two materials.

Material used for side of the can costs $0.015 and material used for the lids costs $0.027.

Surface area of the can is represented by

S = 2πr² + 2πrh ( surface area of the lids + surface are of the curved surface)

Now the function that represents the cost to construct the can will be

C = 2πr²(0.027) + 2πrh(0.015)

C = 0.054πr² + 0.03πrh ---------(1)

Volume of the can = Volume of a cylinder = πr²h

16 = πr²h

$h=\frac{16}{\pi r^{2}}$ -------(2)

Now we place the value of h in the equation (1) from equation (2)

$C=0.054\pi r^{2}+0.03\pi r(\frac{16}{\pi r^{2}})$

$C=0.054\pi r^{2}+0.03(\frac{16}{r})$

$C=0.054\pi r^{2}+(\frac{0.48}{r})$

Now we will take the derivative of the cost C with respect to r to get the value of r to get the value to construct the can.

$C'=0.108\pi r-(\frac{0.48}{r^{2} })$

Now for C' = 0

$0.108\pi r-(\frac{0.48}{r^{2} })=0$

$0.108\pi r=(\frac{0.48}{r^{2} })$

$r^{3}=\frac{0.48}{0.108\pi }$

r³ = 1.415

r = 1.12 inch

and h = $\frac{16}{\pi (1.12)^{2}}$

h = 4.06 inches

Let's check the whether the cost is minimum or maximum.

We take the second derivative of the function.

$C"=0.108+\frac{0.48}{r^{3}}$ which is positive which represents that for r = 1.12 inch cost to construct the can will be minimum.

Therefore, to minimize the cost of the can dimensions of the can should be

Radius = 1.12 inches and Height = 4.06 inches

5 0

3 years ago

A rectangle school banner has a length of 44 inches, a perimeter of 156 inches , and an area of 1496 square inches. The cheerlea

Andrej [43]

Based on the lengths, the cheerleaders' banner is scaled down by a factor of 4.

So, 44 ÷ 4 = 11.

For the perimeter, 156 ÷ 4 is 39.

For the area, you have to do A=bh
(Area = base × height)

The base (length) is 11 inches, multiply that by two to get 22 inches which is the amount for both lengths. If the total perimeter is 39, you have to subtract 22 from that to get the remaining inches which is 17.
17÷2= 8.5 inches. The height is 8.5.

Now you can plug them in
A=bh
A=(11)(8.5)
A=93.5 in^2

The final answer is:
Area = 93.5 in^2
Length = 11 in
Perimeter = 39 in

I hope that helps!

7 0

3 years ago

What’s the factorization of this equation?

ratelena [41]

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8 0

3 years ago

The length of the side of square A is 50% of the length of the square side expressing the area of the shaded area of square

KonstantinChe [14]

Answer:

Let's call the side of square b x. Therefore, the side of square a is 0.5x, making its area 0.25x² and the area of square b is x². This means that the percentage is 25%.

8 0

3 years ago