Can you find the density of an object by how much saltwater (not regular water) it displaces, displacement!?

Question

What would the formula be? I know that D=M/V and in normal water at 4*C density = 1 gram/mL. You can measure the volume of your liquid then measure the volume after you submerse your object. Subtract to get the difference then use that number as V in D=M/V. Question is how would you do it if your liquid had a density of 1.05g/mL not 1.00g/mL like normal water. Where do you put that 1.05?

Some say the density of the liquid doesn't matter. Then, what about the fact that you float more in saltwater than fresh water or a boat rides higher in saltwater than freshwater? Does it really not matter?

Answer 1

The density of the liquid in this case doesn't matter because you are only using the liquid to find the volume of your unknown object.   How much that liquid weighs is irrelevant.

You are correct that a boat rides higher in saltwater than in fresh water.   That is because the boat is not totally immersed but rather,  there is a balance.   The mass of the water displaced needs to be equal to the mass of the boat.   Because the saltwater is more dense,  less water needs to be displaced to achieve the balance.   However,  if you were to sink the boat and totally immerse it,  the volume of saltwater displaced would be exactly equal to the amount of freshwater displaced.   There is no balance needed or achieved.

Answer 2

if you are finding the volume using displacement then it shouldn't matter if it has salt or not because volume is volume and it doesn't matter that it has more mass per mL.

Answer 3

There should be no problem using just about any liquid for density measurement; some times you need to know the density of the liquid, sometimes you don't it depends on the procedure you're using.

If you are measuring volume of the object by immersing in a liquid and noting volume change (such as in a graduated cylinder) then you don't need the density of the liquid because you are directly getting the volume of the object.

So, density = mass/[v2 - v1]

If you are measuring density by the Archimedes method, where the object is weighed in air and then when suspended in a liquid, you need the density of the liquid.

Volume of object  = [mass in air - mass in liquid]/density of liquid

Density = mass (air)/[(mass in air - mass in liquid)/density of liquid]