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If the diameter of a sphere is halved , What effect does this have on its volume & its surfaces area ?​

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Answers:

The new volume is 1/8 of the old volume

The new surface area is 1/4 of the old surface area

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Step-by-step explanation:

Volume:

Let's say the diameter is d = 60

That would make the radius r = d/2 = 60/2 = 30

The volume of the sphere is

V = (4/3)pi*r^3

V = (4/3)*pi*(30)^3

V = (4/3)*(30)^3*pi

V = 36000*pi

Now consider that d = 30 which is half of the original diameter.

So r = d/2 = 30/2 = 15

And also,

V = (4/3)pi*r^3

V = (4/3)*pi*(15)^3

V = (4/3)*(15)^3*pi

V = 4500*pi

The old volume was 36000pi and the new volume is 4500pi

Comparing the two volumes, we see that the reduction factor is

(new volume)/(old volume) = (4500pi)/(36000pi) = 1/8

The new volume is 1/8 of the old volume

smaller volume = (1/8)*(larger volume)

This is equivalent to saying the larger volume is 8 times that of the smaller volume.

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Surface Area:

We'll use the same d and r values from earlier.

The diameter d = 60 leads to r = 30. We'll use this to find the surface area

SA = 4pi*r^2

SA = 4*pi*30^2

SA = 3600pi

For the smaller sphere (d = 30 and r = 15), we have

SA = 4pi*r^2

SA = 4*pi*15^2

SA = 900pi

The reduction factor is (900pi)/(3600pi) = 1/4

The smaller sphere has its surface area 1/4 that of the larger sphere.

smaller surface area= (1/4)*(larger surface area)

This is equivalent to saying the larger surface area is 4 times that of the smaller surface area.

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