Dec. 18, 2018 You need: • Clean paper (2) / Pencil • HW: Explanation of egg in jar – and how to remove. Warm Up: Explain how the egg got into the jar I CAN: determine how heat is transferred in the atmosphere and creates wind.
Mixture of Gases in Air All Other Gases Argon = 0.93% Carbon Dioxide = 0.04%
Let’s make a model! • Write the notes ONTO the correct layer. • Add color to the layers and the pictures. • Cut out the layers and the pictures. • Assemble on your notebook paper. • **Be careful to place them low enough on the page so that they don’t stick out of the top of your binder!!**
Earth’s atmosphere makes conditions on Earth suitable for living things: • It traps energy from the sun keeping the Earth warm. • The heat also keeps water in liquid form (good for life) • It protects Earth from dangerous radiation and meteor collisions.
DENSITY PRESSURE and
DENSITY • The molecules in different objects are arranged differently. They may be closely packed, like in a heavy metal block…
DENSITY • The molecules in different objects are arranged differently. Or they could be spaced out, like in a styrofoam block.
DENSITY • DENSITY describes how closely packed the particles of an object are. LOW density HIGH density
How does this relate to air? • This pushing of air is called AIR PRESSURE. • You felt PRESSURE when you were crammed into the tape square. . . . . . . . . . . . . . . . . . . . . . . . . . ………………………………………………………………………………………………………………………………………… Air at HIGH DENSITY also has HIGH PRESSURE Air at LOW DENSITY also has LOW PRESSURE
Density Columns • If you drew in the molecules for your density column, what would it look like? Spread out for low density Closely packed for high density
Air Pressure in a Syringe Which syringe has the air under more pressure? Low Pressure & Less Dense High Pressure & More Dense
Lower Air Pressure Air Pressure at Different Altitudes Mountains (High altitude) Is air pressure greater at sea level or on top of a mountain? Higher Air Pressure Sea Level (Low altitude)
Air Pressure at Different Altitudes Mountains (High altitude) Magic Balloon: If I want it to be bigger, should I take it to the mountains or the beach? Sea Level (Low altitude)
Back to your notes page… • Altitude, or elevation, is the distance above sea level. • As altitude increases, air pressure decreases. • Air pressure decreases and this also means that density decreases. • Low density can make it difficult to breathe (due to less oxygen)
Air pressure • Air pressure – the result of weight of a column of air pushing down on an area, measured by an instrument known as a barometer. Barometer = Air pressure
COMPRESS Exploring Air with Syringes Based on the investigation: What can air do? A few words you need to know… Compress– means to squeeze into a smaller space Density– the amount of mass (stuff) in a certain amount of space (volume) Air Pressure – the force of air pushing on stuff Barometer– a tool that measures air pressure
What happened? • The fire heats up the air inside the bottle and makes it expand – pushing some air out. • When the fire goes out, the air cools and contracts (takes up less space), creating LOW pressure in the bottle. • Suddenly the HIGH air pressure outside the bottle can "push" the egg inside.
Marshmallow in jar… • Draw the marshmallow in the jar (before and after). Label the pressure and show what happens to the marshmallow. • Explain your answer.
How does heat move? • Heat can be transferred in three ways: radiation, conduction, and convection.
Radiation, Conduction, or Convection? • You feel the warmth of the sun’s rays on your face outside. • You notice your macaroni moving up and down in the boiling water. • At the beach, you step on the hot sand and it burns your feet. RADIATION CONVECTION CONDUCTION
RADIATION • Radiation is the direct transfer of energy by electromagnetic waves. • Radiation does not need any material to travel through! • Energy from the sun gets to us through radiation.
CONDUCTION • Conduction is the direct transfer of heat from one material to another that is touching it. • When a faster-moving molecule bumps into a slower-moving molecule, the slower one speeds up. • Conduction works best in solids. Metal is a good conductor – the heat moves to the girl’s hand. Wood is not a good conductor.
CONVECTION • Convection is the transfer of heat by the movement of particles in a fluid (liquid or gas). • As fluids heat up or cool down, their density changes. Lower-density materials will rise above higher-density materials.
Cold air moves pretty slowly, and stays pretty tightly packed together:
Hot air, on the other hand, goes really fast and expands to fill more space.
So, since hot air is less dense than the surrounding air, it rises, leaving a low-density, low-pressure area behind. Low pressure
Nearby cold air can then rush in to fill low-pressure area left by the rising hot air. This rushing in of cold air is what we call… WIND!!
UNEVEN HEATING The uneven heating of the air that causes wind is created not only by different colors on Earth’s surface, but also by: • Different surfaces (grass vs. snow vs. water, etc.) • Pollution in some areas • Different amounts of sunlight due to seasons, clouds, etc.
During the day, the air over the sand is hotter than the air over the water because the water takes longer to heat up in the Sun. So the wind in the daytime blows TOWARD the beach. WARMER COOLER
But at night, the air over the water is warmer than the air over the sand, because water HOLDS heat longer than the ground. So the wind blows toward the ocean at night. COOLER WARMER
Climate vs Weather • LARGE scale = overall pattern, trend • small scale = daily, weekly, small times • LARGE scale = Over the entire Earth • small scale = tiny area…usually land beside water. Global vs Local winds
Global winds Polar easterlies 1 Prevailing westerlies 2 3 Horse latitudes 4 Trade winds 5 Equator / Doldrums
Coriolis Effect – the effect on the air caused by the rotation of the earth.