Ask your own question, for FREE!
Mathematics 7 Online
OpenStudy (word2):

can you check if i made any mistakes?

OpenStudy (word2):

5. The theme park company is building a scale model of the killer whale stadium main show tank for an investor's presentation. Each dimension will be made 6 times smaller to accommodate the mock-up in the presentation room. How many times smaller than the actual volume is the volume of the mock-up? You can find the answer by dividing the old volume by the new volume. So first we find the new volume of the tank by taking its dimensions (it’s radius) and dividing it by six. new radius = (old radius)/6 new radius = 70/6 new radius = 11.6666666667 And with the new radius, we can find the volume of the entire sphere… V = 4/3 π r^3 V = 4/3 π 11.6666666667^3 V = 4/3π 158.96296297 V = 6482.06481484

OpenStudy (word2):

@agent0smith

OpenStudy (agent0smith):

11^2 is 121, so there is no way 11^3 is 158. Reasonable estimation should tell you that it's way off.

OpenStudy (word2):

Are you sure ? because when i put it in the calculator that's what it gave me

OpenStudy (agent0smith):

Again. Use reasonable estimations to check answers. What you wrote doesn't make sense. 11*11 is 121, so how can 11*11*11 be 158

OpenStudy (word2):

see it's not 11 , its 11.6666666667 , i think that makes a difference

OpenStudy (agent0smith):

Well... that makes no sense, because 11.666 is bigger than 11. So 11.6666 cubed is bigger than 11 cubed...

OpenStudy (word2):

well the reason i got that number is because i did > 70/6

OpenStudy (agent0smith):

What you seem to be saying is that because 11.666 is bigger than 11, then 11.666 cubed should be smaller than 11 cubed

OpenStudy (word2):

should be bigger . 11^3 = 1331 , 11.666^3 = 1587.96296297

OpenStudy (agent0smith):

What you wrote above was not that number though.

OpenStudy (word2):

yes it was , 11.6666666667 .

OpenStudy (agent0smith):

No... check your work on 11.666 cubed.

OpenStudy (word2):

it's still the same ...

OpenStudy (agent0smith):

Go back and look at your working and you'll see it

OpenStudy (agent0smith):

Your original working.

OpenStudy (word2):

70/6 = 11.6666666667 , i don't see why i would use 11.666 when that's not the full answer but let's say that i do 11.666^3 > 1578.6907563 . then ii would time it by 3.14 which gives me 4985.34897477 , then i would times it by the 4/3 >> 6480.9536672

OpenStudy (agent0smith):

You asked us to check your work. If you'll go back and check it, you will notice the mistake I am pointing out.

OpenStudy (agent0smith):

You made a typo. If you look at your original working you will see it

OpenStudy (word2):

ooooh , it should be 1587.96296297

OpenStudy (agent0smith):

Finally lol

OpenStudy (word2):

so the answer will be 6482.06481

OpenStudy (agent0smith):

Yeah looks about right. But keep in mind that isn't what the question asked for

OpenStudy (word2):

_--_ it's not? wow , i am completely lost

OpenStudy (agent0smith):

Go back and read your first post, all the instructions are there

OpenStudy (word2):

55.3846155131752423248504295 ?

OpenStudy (word2):

is how many times smaller than the actual volume is the volume of the mock-up

OpenStudy (word2):

how i got that was i took the volume of the actual tank and divided by the mock up tank . the volume of the actual tank is 359006.6675

OpenStudy (agent0smith):

That's just a random number. And isn't correct. What is the volume of the big one?? If the radius is 6 times less, the volume should be 6^3 times less, so you know what you're looking for.

OpenStudy (mjdennis):

Wait, 55-point something is your final answer?

OpenStudy (word2):

its not a random number, the volume of the big one is 359006.6675. the volume of the small one is 6482.06481481

OpenStudy (word2):

and yes @mjdennis

OpenStudy (agent0smith):

Show work since your volume is wayyyyyy off

OpenStudy (word2):

okay , V=4/3 (3.14)*(70)^3→ V=(1.3)*(3.14)*(343000)=1,400,126 Then I will have to divide the volume of the sphere by four 1,436,026.67/4= 359,006.6675. this is how i received the big tanks volume. this part is correct according to my teacher. so next i took the volume of the small tank , which we agreed was 6482.06481 and dived them together to receive 55.3846155131752423248504295 or just 55. i didn't just pick any random numbers

OpenStudy (agent0smith):

Explain why you divided by four

OpenStudy (word2):

i divided by four because the tank is a quarter-sphere sized tank

OpenStudy (mjdennis):

And explain why you did not divide the volume of the model by four?

OpenStudy (agent0smith):

Then why didn't you do that for the smaller tank?

OpenStudy (agent0smith):

It also would have been helpful had all the information been posted at the start. You never mentioned it was a quarter tank...

OpenStudy (word2):

sorry , i didn't think i needed to divide by four . opps , okay so if i divide the 6482.06481 by 4 it would give me 1620.5162025 .

OpenStudy (word2):

then im guessing that i would take the 1620.5162025 and divide it by the 359006.6675? and this would give me my answer?

OpenStudy (agent0smith):

Yes. And the scale model would have to be a quarter tank too, or else... it's not a scale model, so yes you'd need to divide the spheres volume by 4

OpenStudy (word2):

okay then my answer will be 221.5384622172575902

OpenStudy (word2):

this means that the mock up tank is 221 times smaller then the actual tank

OpenStudy (agent0smith):

Much better It would be exactly 6^3 like I mentioned earlier but that's probably fine

OpenStudy (word2):

oo thank you , i understand this much better now.

OpenStudy (agent0smith):

It would be 6^3 since volume is a function of radius cubed, so if you decrease radius by a factor of 1/6, you decrease volume by a factor (1/6)^3

OpenStudy (word2):

okay. i understand

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!