SOLUTION: The surface area of a solid clay hemisphere is 10cm^2. A larger solid clay hemisphere has a surface area of 40cm^2. If the larger hemisphere weighs 2 pounds, how many pounds doe

Algebra ->  Surface-area -> SOLUTION: The surface area of a solid clay hemisphere is 10cm^2. A larger solid clay hemisphere has a surface area of 40cm^2. If the larger hemisphere weighs 2 pounds, how many pounds doe      Log On


   



Question 1177846: The surface area of a solid clay hemisphere is 10cm^2.
A larger solid clay hemisphere has a surface area of
40cm^2. If the larger hemisphere weighs 2 pounds,
how many pounds does the smaller one weigh?

Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

ratio: 10%2F40=1%2F4
let the weigh of smaller one be x
x%2F2=1%2F4
x+=+1%2F2
the smaller one weigh 1%2F2 pound

Answer by ikleyn(52798) About Me  (Show Source):
You can put this solution on YOUR website!
.

            The solution and the answer in the post by  @MathLover1 are both  ABSOLUTELY  WRONG.

            I came to bring a correct solution.


The ratio of the surface areas of the two solid hemispheres is  4,  according to the condition.


It means that the the ratio of their linear dimensions is  2  (larger to smaller).


Hence, the ratio of their volumes is  8.


Since the material they are made is the same, the ratio of the masses  (weights)  is  8.


ANSWER.  The smaller hemisphere weight is   1%2F4   of a pound.

Solved   (correctly).

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For your safety,  ignore the post by  @MathLover1.





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Looking into her activity in last several days, I start thinking that

@MathLover1 presents a real danger for any visitor to this forum, because she provides wrong solutions even to simplest Math problems.


See my notes to her posts in past two days

https://www.algebra.com/algebra/homework/Finance/Finance.faq.question.1177850.html

https://www.algebra.com/algebra/homework/Volume/Volume.faq.question.1177847.html

https://www.algebra.com/algebra/homework/Surface-area/Surface-area.faq.question.1177846.html

https://www.algebra.com/algebra/homework/Triangles/Triangles.faq.question.1177800.html

https://www.algebra.com/algebra/homework/Triangles/Triangles.faq.question.1177804.html