Please help?

Question

In the laboratory you are given a cylindrical beaker containing a fluid and you are asked to determine the density of the fluid. You are to use a negligible mass and unknown spring constant attacked to a stand An Irregularly shaped object of known mass and density hangs from the spring. You may also choose a metric ruler, a stopwatch or a string to complete the task.
1.Exp. how you could experimentally determine the density of the fluid.

Answer 1

Ok, lets take the spring first. Measure the expansion of the spring with the metric scale, lets say L1. This gives you the spring constant k = m*g/L1.

m= known mass of the object. g = gravitaional acceleration.

Now place the beaker so that the object is submerged in the fluid. Again measure the expansion of the spring. Let's say this one L2. So you work out the appearent weight.
W ' = k.L2

So, weight decreased by a value of mg - W ' = dw (say).

Now, you know the density of the solid object, let's say, d.

So volumn V =m/d.

So displaced volumn of fluid = V. Let's say fluid's density = D. So dw =VDg.

Which implies, D= dw / vg.


Hope this helps you a bit :-)