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If something weighs say 3.680g and the other weighs 3.130g,

is it still possible for the one that weighs more to be 'smaller' as in have a larger sa/vol and be more efficient than the one that weighs less?
 

InteGrand

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If something weighs say 3.680g and the other weighs 3.130g,

is it still possible for the one that weighs more to be 'smaller' as in have a larger sa/vol and be more efficient than the one that weighs less?
Not sure what you mean by efficient, but yes, it is possible for a smaller volume object to weight more than a larger volume object – this happens iff the former object has a greater density than the latter.

It is also possible for a smaller surface area object to weigh more than a larger surface area object.
 

Nailgun

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If something weighs say 3.680g and the other weighs 3.130g,

is it still possible for the one that weighs more to be 'smaller' as in have a larger sa/vol and be more efficient than the one that weighs less?
yeh

d=m/v

so m/d = v

you could have something reallllly dense and it would be alot 'smaller' in terms of volume (and surface area probs)

but i just realised you're talking about that bio thing of surface-area to volume ratio

idk
 

leehuan

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yeh

d=m/v

so d/m = v

you could have something reallllly dense and it would be alot 'smaller' in terms of volume (and surface area probs)

but i just realised you're talking about that bio thing of surface-area to volume ratio

idk
Since when was density a part of prelim/HSC physics
 

Nailgun

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Since when was density a part of prelim/HSC physics
since yr 7 science lele
damn i rearranged the thingo wrong and edited so noone would notice
you just had to quote it first lelel :lol:
 

leehuan

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since yr 7 science lele
damn i rearranged the thingo wrong and edited so noone would notice
you just had to quote it first lelel :lol:
In Year 7 I was just learning about ecosystems and how do you seperate a mixture and writing a scientific method
 

Nailgun

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In Year 7 I was just learning about ecosystems and how do you seperate a mixture and writing a scientific method
lellee well a hsc phys specific example would be that the force applied from gravitational acceleration varies depending on the density of the crust at that point, as having a higher concentration of like heavy stuff like iron means a greater mass per unit volume, and hence a stronger gravitational strength at that point radially from the centre of the earth
 
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Thanks for the replies, I still have no idea lol.. I'm a bit backwood wit mafs.

I'm referring to those coke bottle lollies btw.. had to do an experiment with them.
 

InteGrand

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Thanks for the replies, I still have no idea lol.. I'm a bit backwood wit mafs.

I'm referring to those coke bottle lollies btw.. had to do an experiment with them.
Don't need to think of it mathematically, can just think of it intuitively: a (non-hollow) cylinder of foam will clearly weigh less than a (non-hollow) cylinder of wood of the same or even slightly smaller size (this is because foam is less dense than wood).
 

Nailgun

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Thanks for the replies, I still have no idea lol.. I'm a bit backwood wit mafs.

I'm referring to those coke bottle lollies btw.. had to do an experiment with them.
basically it is possible for the one that weighs more to have a lower surface-area to volume ratio (what you are asking for im pree sure)

for any given volume a perfect sphere will have the lowest surface area to volume ration, while you can go upto infinity (i.e. no maximum shape) for a given volume (from wikipedia)

can you give us a little more detail on what you have to do?
 

leehuan

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lellee well a hsc phys specific example would be that the force applied from gravitational acceleration varies depending on the density of the crust at that point, as having a higher concentration of like heavy stuff like iron means a greater mass per unit volume, and hence a stronger gravitational strength at that point radially from the centre of the earth
Yea but ρ=m/V though :p
 

leehuan

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Thanks for the replies, I still have no idea lol.. I'm a bit backwood wit mafs.

I'm referring to those coke bottle lollies btw.. had to do an experiment with them.
A bowling ball is probably heavier than a beach ball of the same diameter
 
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basically it is possible for the one that weighs more to have a lower surface-area to volume ratio (what you are asking for im pree sure)

for any given volume a perfect sphere will have the lowest surface area to volume ration, while you can go upto infinity (i.e. no maximum shape) for a given volume (from wikipedia)

can you give us a little more detail on what you have to do?

Based on my hypothesis I need the one that weighs more to have a larger surface area to volume ratio.

I know larger cells have a smaller sa/vol ratio, and that small cells with large sa/vol ratios are more efficient (e.g. a small cup of coffee will cool quicker than a large cup of coffee)

The coke bottles appear to be the same size right, but one weighs more than the other.

Osmosis should occur quicker in the one with the largest sa/vol ratio. I'm just not sure if that can be the one that weighs more.

The person that was responsible for taking measurements was too slack to do so, so I'm left guessing.
 

Nailgun

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Based on my hypothesis I need the one that weighs more to have a larger surface area to volume ratio.

I know larger cells have a smaller sa/vol ratio, and that small cells with large sa/vol ratios are more efficient (e.g. a small cup of coffee will cool quicker than a large cup of coffee)

The coke bottles appear to be the same size right, but one weighs more than the other.

Osmosis should occur quicker in the one with the largest sa/vol ratio. I'm just not sure if that can be the one that weighs more.

The person that was responsible for taking measurements was too slack to do so, so I'm left guessing.
ok so basically

then you have a problem lol

one will weigh more than the other based on either 1) one is more dense than the other or 2) one is has more volume than the other

or 3) both

basically what we know is that they are the same shape
so that means the surface area is dependent on the volume

if the reason for a weight difference is because of a difference in density only, that means both will have the same surface area to volume ratio
if the reason for a weight difference is because of a difference in volume only, that means they will have different surface area to volume ratios, and actually the one that weighs more will have a greater volume and so will have a lower surface to volume ratio lol

edit: considering that they are lollies i would assume volume would be same, and density would be the variation
so they should have same sa:v ratio


edit2: now that i think about it, if the shapes are the same then sa is directly proportional to v, and if v changes so does sa and so the ratio will be the same?
 
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leehuan

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I remember doing this prac in prelim bio but nothing about it though
 

leehuan

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Pretty sure we did it with cubes of agar jelly or something? Don't remember anything from bio lelelel
That's right, those jelly cubes

That's about all I remember too :D
 
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