E.T. 2/25Draw the following (beach, water, and sun) in the “notes” section of your science notebook
THE STORY OF MR. SEABREEZEWhy we have weather Imagine yourself at the beach during the day and then at sunset -- what, if any, differences are there?
The ground and water are heated by the sun through radiation (electromagnetic waves primarily in the infrared, visible, and ultraviolet portion of the electromagnetic spectrum). Add “radiation” to your picture. Radiation
Think about the following questions; do not answer out loud but be prepared to give an answer if called upon: On a sunny summer day at the beach which is warmer, the ocean water or the sand? At night at the beach, after the sun has gone down, which is warmer, the ocean water or the sand? .
Specific heat is the measure of the heat energy required to raise the temperature of a given amount of a substance by one degree. Differential heating -- this is why we have weather! Sand heats up faster and cools down faster than water with radiation from the sun (add this to the picture in your notebook) Water has a higher specific heat than sand Specific Heat and Heat Capacity
Conduction • The air touching the sand is heated by conduction, which is when energy is transferred by molecules slamming into one another. • Add “conduction” to your drawing
Think about the following questions; do not answer out loud but be prepared to give an answer if called upon: What happens when the burners are lit on a hot air balloon? What happens when the burners turn off?
The same principle is true of hot or cold air in the atmosphere: -Warm air rises - Cold air sinks
Convection • As the warm air over the land warms up, it begins to rise. As the warm air rises, the cooler air from over the water flows in to take its place. • This movement of air is convection, or molecules moving from one place to another. • Add “convection” to your beach drawing
The body of air over Olympia is low pressure but the air in Seattle is high pressure. Which way is the wind blowing? 1) Seattle to Olympia 2) Olympia to Seattle
Homework -- on separate sheet of notebook paper to turn in. Write severalmeaningful haikus or one long poem using the following terms with their relation to the formation of wind: specific heat, conduction, convection, air pressure, electromagnetic radiation, wind.
Entry Task 2/11/09Discuss with classmates How does an airplane wing work in terms of air pressure?
When it is cold and you exhale, why do you see your breath? Why does this not happen when it is warmer?
About how much water vapor can the air hold if it is zero degrees outside? What if it is 40 degrees?
Dew point Why does dew form on the ground?
Dew point Why does dew form on the ground?
Just Dew It! -- LAB In lab groups of two or three people, perform this lab. MAKE DATA TABLE AND ANSWER QUESTIONS ON YOUR OWN SHEET OF PAPER. DO NOT WRITE ON THE CLASS SET OF LABS.
Entry Task What conditions are necessary for clouds to form?
Cloud in a bottle – LAB (put this title in “textbook”) Investigative question: What conditions are necessary for clouds to form? Hyposthesis: (if, then, because)
Cloud in a bottle – LAB (put this title in “textbook”) PART A • Fill jar 1/3 full of warm water • Fill metal can with ice and place on top of jar • Shine flashlight through empty space in jar • Make observations of what is happening in your “textbook”
PART B • Fill jar 1/3 full of warm water • Strike match and drop into water • Immediately put ice (in metal can) on top of bottle • Make observations of what is happening in your “textbook” while shining flashlight through empty space in jar
Questions to answer in “textbook” • What is another condition, besides moisture and cool air, necessary for cloud formation? • In nature how does moisture get into the atmosphere? • Once in the atmosphere, why would water vapor cool? • What in nature would act as the smoke that was used in lab?
Cloud formation(take notes in “textbook” after lab) • Evaporation: water molecules absorb thermal energy from the sun. High energy molecules leave as gas. • Gases are warmed by radiation from sun, and they expand, rise, and cool. • Condensation: The warm water vapor rises until it cools to the point where it condenses around condensation nuclei in the atmosphere.
So........ • The amount of energy in the system is conserved: • the energy absorbed by the molecules during evaporation is equal to the amount of energy released during condensation.
Evaporative cooling Demonstration
What is temperature measuring? Definition of temperature: The average kinetic energy of molecules in a substance
Make an analogy and write it down Your job is to make an analogy for the process of evaporative cooling.
Example analogy: The really good college basketball players sometimes leave to go to the NBA, leaving the college basketball “pool” of players less talented. The good players are like high energy molecules, and the NBA would be like a cloud of gas. The “pool” of college basketball players are like a body of liquid which is left with lower energy molecules, and so the average kinetic energy is lower.