Question

Alex designed the model of a cylindrical water tank to be installed in a park. The model has a radius of 4 cm and a height of 12 cm. The dimensions of the actual water tanks that will be installed in the park are 5 times larger than the model. The total surface area of the actual water tanks, rounded to the nearest whole number, is _________ cm2. Use 22 over 7 for pi.

Answer 1

@ivettef365 @ganeshie8

Answer 2

start with calculating the total surface are of model cylinder

Answer 3

Model :

r = 4
h = 12

total surface area = \(2\pi r^2 + 2\pi r h\)
= ?

Answer 4

one second let me calculate it

Answer 5

hmm, my answer doesn't seem like it would be right :/ I got 5, 980. 55

Answer 6

.44*

Answer 7

check again

Answer 8

and keep in mind, we are calculating surface area of model only. actual cylinder we will calculate later.

Answer 9

wolfram says 402.3

http://www.wolframalpha.com/input/?i=2*22%2F7*4%5E2%2B2*22%2F7*4*12

Answer 10

hmm :/ then i'm doing something wrong

Answer 11

I kept multiplying 2 x 3.14 and i'm getting 6.28

Answer 12

hmm ok check it later. lets trust wolfram... its super smart :)

Answer 13

so total surface area of model = 402.3

Answer 14

okay !

Answer 15

since, the dimensions of actual cylinder are 5 times larger, the surface area will be 5^2 = 25 times larger.

Answer 16

so we multiply the model area with 25 to get the actual cylinder area :

actual cylinder area = 402.3*25 = ?

Answer 17

10057. 5

Answer 18

yeah round it to nearest whole number, it wud be : 10057

Answer 19

http://www.wolframalpha.com/input/?i=%282*22%2F7*4%5E2%2B2*22%2F7*4*12%29*25

Answer 20

you can use wolfram as your online calculator if it helps..

Answer 21

I will from now on. so the answer is 10057?

Answer 22

yes

Answer 23

thank you ! sorry im asking for so much help

Answer 24

np you welcome :)