In the laboratory, you are given a cylindrical beaker containing a fluid and you are asked to determine the density [tex]\rho[/tex] of the fluid. You are to use a spring of negligible mass and unknown spring constant k attached to a stand. An irregularly shaped object of known mass m and density D > [tex]\rho[/tex] hangs from the spring, so that the object (but non of the spring) is immersed in the fluid. You may also choose from among the following items to complete the task.
- A metric ruler
- A stopwatch
Explain how you could experimentally determine the density of the fluid. Show explicitly, using equations, how you wuill use your measurements to calculate fluid density [tex]\rho[/tex]. Start by identifying any symbols you use in your equations.
Fbuoyancy = [tex]\rho[/tex]fluidVobjectG
[tex]\rho[/tex] = m/v
[tex]\rho[/tex]obj/[tex]\rho[/tex]fluid = Vfluid/Vobj
The Attempt at a Solution
I'm pretty much at a loss on this one. Seeing as I have the density of the object and its volume, I could plug that into the 3rd equation. However, I'm wondering if the third equation only applies to floating objects, as in this experiment, the object will sink. I can't figure out a way to obtain the fluid's mass, either. Thank you for the help.