Question

1. note: objects a - c are floating in pure water and object d sank in pure water. approximate the four objects’ densities. be sure to include units.

a.____
b.____
c.____
d.____

Explanation:

Step1: Recall density - buoyancy relationship

An object floats if its density ($
ho_{object}$) is less than the density of water ($
ho_{water}= 1\ g/cm^{3}$) and sinks if $
ho_{object}>
ho_{water}$.

Step2: Analyze object A

Object A is floating with a large portion above - water. So its density is much less than that of water, approximately $
ho_A = 0.3\ g/cm^{3}$.

Step3: Analyze object B

Object B is floating with about half of it above - water. So its density is approximately $
ho_B=0.5\ g/cm^{3}$.

Step4: Analyze object C

Object C is floating with a small portion above - water. So its density is close to that of water, approximately $
ho_C = 0.9\ g/cm^{3}$.

Step5: Analyze object D

Object D sinks, so its density is greater than that of water. An approximate value could be $
ho_D = 1.2\ g/cm^{3}$.

Answer:

A. $0.3\ g/cm^{3}$
B. $0.5\ g/cm^{3}$
C. $0.9\ g/cm^{3}$
D. $1.2\ g/cm^{3}$