Solids Expanding and
Contracting in our Daily Lives
- Why is it
important to place gaps at regular intervals in sidewalks?
In the summer the sidewalk expands and in the
winter it contracts. The gaps allow space for the expansion and contraction so
the sidewalk doesn’t crack.
- Concrete and
steel expand at almost the same rate. Explain why this is important in the
construction of tall buildings.
If they did not expand and contract at the same
rate, there would be many cracks in the building and it might fall down.
Gases Expanding and
Contracting in our Daily Lives
- Explain how a
hot air balloon is lifted from the ground.
When the gas particles inside the hot air
balloon are heated, they expand and some escape from the bottom of the balloon.
This causes there to be fewer air particles inside the balloon then outside the
balloon. The less dense hot air will float on more dense cold air so the
balloon rises.
c) Once in the air, the burner is turned off
and the balloon drifts along with the wind. What will eventually happen to the
air inside the balloon?
Cooler air will enter the balloon and the air
inside will become more dense. The balloon will begin to go down.
Liquids Expanding and
Contracting in our Daily Lives
- A bowl of hot
soup was left on the table to cool. After a few minutes, the amount of
soup in the bowl appeared to have decreased? Why?
The soup may have cooled down and there seems
to be less soup because the particles become closer together (contract) and
become denser.
- When
manufacturers pack liquids into bottles and jars, they leave a small space
at the top before putting on the lids. Why?
The space allows for the liquid to expand
without causing the bottle to break.
- Mercury
expands and contracts faster than alcohol. Which liquids would be better
in a thermometer?
Mercury will tell the temperature faster, but
it will also contract faster so it will drop more quickly making it harder to
read the temperature. Also, mercury is poisonous!
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