Answer:
A substance in its liquid state is closer to the density of its solid phase than the density of its gaseous phase.
Explanation:
For a substance in its liquid state we can expect the density of the substance more closer to the density of its solid state than its gaseous state because the the inter-molecular space is much close near to incompressible in the liquid state and the the inter-molecular force of attraction is much higher as compared to gaseous state.
In contrast to the molecular properties in liquid state gases have almost negligible inter-molecular force of attraction and very huge inter-molecular spacing which makes it well compressible.
1st is sublimation
2and is melting
3red is melting
4th is sublimation
sublimation is just "skipping" the liquid phase / state
Answer:
The position is 8.18cm from the mirror.
Nature is b=virtual
Size is 1.82cm
Explanation:
Note that for a convex mirror, the image distance and the focal length are negative;
Given
Object height H0 = 4cm
object distance u = 18cm
Radius of curvature R = 30cm
Since f = R/2
f = 30/2
f = -15cm
Recall that:

Since the image distance is negative, this shows that the image is a virtual image.
To get the size:

Complete Question
A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.
What is the refrigerator's coefficient of performance? COP
(b) What If? What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump? COP
Answer:
a

b
Explanation:
From the question we are told that
The lower operation temperature of refrigerator is
The upper operation temperature of the refrigerator is 
Generally the refrigerators coefficient of performance is mathematically represented as

=> 
=> 
Generally if a refrigerator (operating between the same temperatures) was instead used as a heat pump , the coefficient of performance is mathematically represented as
=>
=>
A. Forced vibrations, such as those between a tuning fork and a large cabinet surface, result in a much lower sound than was produced by the original vibrating body.