Question

the diagram below represents a cylinder which contains four different liquids, w, x, y, and z, each with a different density (d) as indicated. a piece of solid quartz having a density of 2.7 g/cm³ is placed on the surface of liquid w. when the quartz is released it will pass through
a) w and x, but not y or z
b) w, x, y, and z
c) w, x, and y, but not z
d) w, but not x, y, or z

Explanation:

Step1: Recall density - sinking and floating principle

An object sinks in a fluid if its density ($
ho_{object}$) is greater than the density of the fluid ($
ho_{fluid}$), and floats if $
ho_{object}<
ho_{fluid}$.

Step2: Compare quartz density with liquid densities

The density of the solid quartz is $
ho_{quartz}=2.7\ g/cm^{3}$. The density of liquid $W$ is $
ho_{W} = 1.0\ g/cm^{3}$, the density of liquid $X$ is $
ho_{X}=1.8\ g/cm^{3}$, the density of liquid $Y$ is $
ho_{Y}=2.3\ g/cm^{3}$, and the density of liquid $Z$ is $
ho_{Z}=3.0\ g/cm^{3}$.
Since $
ho_{quartz}>
ho_{W}$, $
ho_{quartz}>
ho_{X}$, and $
ho_{quartz}>
ho_{Y}$, but $
ho_{quartz}<
ho_{Z}$, the quartz will pass through $W$, $X$, and $Y$ but not through $Z$.

Answer:

C. $W$, $X$, and $Y$, but not $Z$