Question

Find the surface area of the cylinder.
2009.6 in.2
401.9 in.2
803.8 in.2
602.9 in.2

Find the volume of the cylinder.
1607.7 in.3
2,845.7 in.3
6,430.7 in.3
401.9 in.3

Answer 1

can you guys help me?

Answer 2

The cylinder wall area is:
2*pi*r*h
The area of each endcap is:
pi*r^2

The volume of the cylinder is:
pi*r^2*h

Answer 3

whats h

Answer 4

h = height

Answer 5

is it 1607.68

Answer 6

Just plug in the numbers into qwe's area equation.

Answer 7

i did the equation is it the answer i posted

Answer 8

Sorry, I had to figure out what you did.

Yes, you are correct.

1607.68 is the answer using 3.14 as pi.

Answer 9

yay ok thx

Answer 10

what about the area?

Answer 11

Okay, first find the cylinder wall area using 2*pi*8^2

Answer 12

ok lemme do tht

Answer 13

401.92

Answer 14

Correct!!
Now find the area of one endcap using pi*8^2

Answer 15

ok ima do that now

Answer 16

200.96

Answer 17

Correct again!! :-)

Okay, but now we're in a little dilemma here...
You have 4 answers, 1 of wich is absurd, 1 of which is the area of the cylinder wall alone, 1 is the area of the wall and 1 endcap, and 1 is the area of the wall and 2 endcaps.

I'm going to guess that the answer is the cylinder wall and 2 endcaps, if that's okay with you.

So that being the case, I would take the area of the single endcap you just got and double it to give you the surface area of both endcaps.

Then I would add that number to the area of the cylinder wall.

Answer 18

803.84

Answer 19

Correct again!

You'll be teaching ME this stuff pretty soon now! :-)

Answer 20

haha lol ya

Answer 21

thx alot if you wouldnt mind would you check my answer to this other question?

Answer 22

Which other question?

Answer 23

Find the volume of the given cone.

320 in3
1,244 in3
415 in3
622 in3
Im pretty sure its d but im not very good at these

Answer 24

Heheh...would you believe I've never taken the volume of a cone before? I had to look up the formula!

But yes, I got 414.69 using my calculator (which takes pi out to a zillion places)

Answer 25

so would it be c

Answer 26

Yes, I would choose C. :-)

Answer 27

ok thx

Answer 28

The volume formula for a cone is
v = 1/3 pi r^2 h

So I did pi * 6^2 * 11 and got 1244.0706908215581224312067797787

Then I divided that by 3 to get: 414.69023027385270747706892659289

Answer 29

wooo long number

Answer 30

Yeah...the wonder of calculators, eh? :-)

Unfortunately it can cause minor problems when limiting numbers to 2 places because, as you can see, the final answers have small discrepencies.

But as long as you can recognize what's going on, then it's usually safe to pick the closest answer as I/we did here. :-)

Answer 31

ya bai! thx for the help

Answer 32

No problem again!

Be well! :-)