# Physics

Topics: Water, Atmospheric pressure, Boiling Pages: 4 (1470 words) Published: January 1, 2013
Physics
pg194-195
2.why does barometric pressure drop when there is a storm?
-Barometric pressure drops because there are powerful winds in the higher atmosphere that blows in or suck out in any direction and change at random times. 3.Our ears pop when we ride in an airplane or when we drive to the mountains,why? - Our ears pop when we ride in an airplane or when we drive to the mountains because the air high above the surface of the earth is less dense than air near the surface.As you ascend in an airplane(or go up in the mountains)the air pressure decreases,and the air trapped in your inner ear will cause your eardrums to push outward.This expansion causes not only the discomfort you feel before your ears "pop",but also a decrease in hearing ability,because the pressure on your eardrums makes the sound harder to transmit.your body can equalize the pressure between your inner ear and the atmosphere by allowing some air from your inner ear to to escape through the Eustachian tubes,two small channels that connect the inner ears to the throat,one on each side.When they open,you feel the pressure release and you hear the change because it's happening in your ear this equalization of pressure is the "pop" 4.Steel is denser than water.Ships are made of steel.Ship float in water.How is this possible? -Because they are not solid shapes.They are shaped so as to be lighter than the water when you look at their overall volume.It's like a childs ballon.Uninflated,it lies on the ground and doesn't move.But fill it with air and floats in the air.Suddenly ther is less density than there was. 5.what is the meaning of "tip of an iceberg"?

-A small evident part or aspect of something largely hidden: afraid that these few reported cases of the disease might only be the tip of the iceberg. 6.why is there a small hole on the barrel of a nonretractable ball point pen? -It is there to allow the air to enter the interior of a pen while the ink flows out.This...