Please help me with this thing?

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 sprinf of negliglble mass and unknown spring constant k attacked to a stand. AN irregularly shaped object of known mass and density hangs from the spring. YOu may choose a metric ruler, a stopwatch, and string to complete the task.
a. Exp. how you could experimentally determine the sping constant
b. The spring object system is now arranged so that the object but none of the spring is immersed in the unknown fluid. Describe any changes that are observed in the system and explain why they occur.
c. Exp. how you could determine the density of the fluid.
d. Show explicitly, using equations, how you will your measurements to calculate the fluid density.

Answer 1

a) see http://www.ap.stmarys.ca/demos/content/mechanics/spring_constant/spring_constant.html
b)The spring is less extended than when hanging freely in air.
c-d) calculate the volume of the object from the given mass and density
you know k from a) F=kmg------ extended distance
buoyant force on object in fluid = vol density
Force on submerged object F=k(mg-vol density of fluid)---new extended distance acts like a lesser mass

Answer 2

I will tell you possible ways of finding each question, to the best of my gr.12 physics knowledge lol.

a) use oscilliating motion of the irregular object on the spring (i'm not sure if this would work, could give it a try?)
b) Once the object is submerged, the volume of the object can be found, therefore the density can be found. The amount of force that is reduced could give the relative density of the liquid.

I have no idea for c and d, but maybe my a and b suggestions would help. Again, sorry if none of this helps. Good luck on the lab.