geometry please help :) Two similar solids are shown below. Two similar solids are shown. The length of the smaller solid is 5 feet and its volume is 875 cubic feet. The length of the bigger solid is 7 feet. Its volume is not known. What is the volume of the larger solid? 1750 ft3 1000 ft3 7000 ft3 3500 ft3
What is the ratio of the lengths (small to large).
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im not sure what your asking. i just attached a picture
I am confused too. In the problem it says the length of the larger solid is 7feet. In the picture it shows a length of 10 feet. Which one is correct?
im sorry my fault. the question is, What is the volume of the larger solid? ignore the original post.
I'd defer to the picture, though it could be 2 valid exercises mixed up
my fault, the picture is correct
Okay, I am ignoring the original post. The ratio of the lengths of the small solid to the large solid is 5 to 10 or 5:10 = 1:2.
So the ratio of the lengths is 1:2. If I remember correctly my geometry textbook calls this the "scale factor".
or \(\bf \cfrac{10}{5} = \cfrac{v_2}{v_1}\)
What will the ratio of the volumes be?
incorrect.
@jdoe0001 you are close but not quite correct. The ratio of the volumes is not equal to 10:5 or 5:10.
to get the ratio of the volumes you must CUBE the ratio of the lengths.
ratio of volumes = (ratio of lengths)^3 = (1:2)^3 = 1:8
hmmm, that sounds right :)
\(\bf \cfrac{10^3}{5^3} = \cfrac{v_2}{v_1}\)
\[\frac{ 8 }{ 1 } = \frac{ v _{2} }{ v _{1} }\]
Yes, @jdoe0001, that it correct, however I present the same equation in simplified form.
indeed
so similar means in this case that all the lenghs are 2:1 ?
How's it going @LaurenAshley1201 ?
Yes @nistal.
@LaurenAshley1201 \[\frac{ 8 }{ 1 } = \frac{ v_{2} }{ 875 }\]
Cross multiply to find your volume for the larger solid. Ask me a question if this does not make sense.
>The length of the bigger solid is 7 feet. (posted) On the diagram, the length is shown as 10. So, I'm assuming the length of the second solid is 10. I need to recalculate.
Theorem: If two solids are similar, the cube of the scale factor of the two solids is equal to the ratio of the volumes. (5/10)³ = 875/V where V is the volume of the larger solid 1/8 = 875/V @LaurenAshley1201 Solve the equation for V.
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