Answer:
a. Temperatures increase can change a solid to a liquid, but cannot change a liquid to a solid
b. The particles in a solid are much closer together than the particles in a liquid.
Explanation:
Any material expands when heated and contracts when cooled. So, when a body is heated to a particular temperature, it starts melting and changes into a liquid.
As the material expands the distance between the atoms or molecules increases and it will become a liquid. So it can move around the material. It doesn't become solid on further heating. But water is an exception where it contracts when heated from 0° to 4° C.
In solids, these atoms or molecules are closely packed. It is rigidly fixed.
The solid, as well as the liquid, has a definite volume, but the liquid does not have a definite shape.
A foliated texture
i have to write 20 characters so ignore this
15 = a+(3-1)d
23 = a+(7-1)d
simultaneous eqs. solve for a and d
Answer:
2.464 cm above the water surface
Explanation:
Recall that for the cube to float, means that the volume of water displaced weights the same as the weight of the block.
We calculate the weight of the block multiplying its density (0.78 gr/cm^3) times its volume (11.2^3 cm^3):
weight of the block = 0.78 * 11.2^3 gr
Now the displaced water will have a volume equal to the base of the cube (11.2 cm^2) times the part of the cube (x) that is under water. Recall as well that the density of water is 1 gr/cm^3.
So the weight of the volume of water displaced is:
weight of water = 1 * 11.2^2 * x
we make both weight expressions equal each other for the floating requirement:
0.78 * 11.2^3 = 11.2^2 * x
then x = 0.78 * 11.2 cm = 8.736 cm
This "x" is the portion of the cube under water. Then to estimate what is left of the cube above water, we subtract it from the cube's height (11.2 cm) as follows:
11.2 cm - 8.736 cm = 2.464 cm