|Tom Heffernan|| Intro
Explain today's lesson
Body of the lesson
|Student will learn that the air around us is composed of gases, moisture and small particles like dust and pollen. Student will learn that air has mass and characteristics like temperature, pressure and speed. Student will learn that warm air rises. The student gains experience at forming hypothesises, conducting experiments, working in groups, recording data and reporting findings to the class.|
|Learners & Context|
|Room Setup||Media Used|
|Standard public school science classroom equiped with at least one computer that is linked to the internet. An overhead projector linked to the computer would be very helpful.|
|To Bring||To Do Ahead|
|Materials: 2 yardstick (meter sticks) 2 identical balloons 2 twist ties for the balloons 3 eight inch pieces of string 1 table or desk 1 weight (books will do) Air Movement Experiment: Materials: heavy paper or thin cardboard long piece of thread or string utility lamp with 100 watt bulb one small piece of tape 3 small pieces of tape.||Rehearse the experiments.|
Ask the students to imagine the ground we stand on as being at the bottom of a vast ocean of air. Explain the air above us is always pressing down on us the same way that ocean water presses down on fish and submarines in deep depths of the ocean. If we were standing on the bottom of the ocean we would be curshed by the pressure. So, why aren't we crushed by the pressure of air? Well, obviously, it is because air is much lighter than water. A gallon of water weighs approximately 6 lbs. How much does a gallon of air weigh? Nothing? Well, not quite nothing. It is light but it is does weigh something. In fact it weighs more then some things. And there are some things that are lighter than air. Discuss some things that are lighter than air: helium balloons, hot air balloons, smoke, clouds, steam. What do all these things have in common? They're all gases or in a gaseous state. Something to think about: If a hot air balloon rises would a cold air balloon sink? If yes, what makes hot air lighter than cold air -- they are both air. See there's more to air than most people think.
|8:04 AM|| Explain today's lesson
Today we will be learning more about air and about how the air effects the weather. Overview: The main theories and principles are touched upon. a) how air behaves and why: movement including wind, warm air rising. b) experiments will be done to determine if air has mass, if warm air rises. c) the make up of air: gases, vapor, etc. d) Perform experiments. e) Conclusion: Results of the experiments and the relationship between air movement and the weather.
Body of the lesson
a) Air is composed of nitrogen (78%) oxygen (21%) carbon dioxide, argon, helium and varying amounts of moisture and particulate matter like dust and pollen. These things in the air give it its weight. The way vegetables and noodles in a soup make a cup of soup weigh more than a cup of water. Thus, the things "in" air effect how much it weighs. We can perform an experiment to show that while air seems to weigh nothing, it actually does have weight and is pressing down on everything all the time. (Balancing balloons) b) How air behaves: Air has characteristic behaviors: It as temperature that changes. It has speed. Wind is just fast moving air. We measure wind speed in miles per hour. In other parts of the world wind is measured in kilometers per hour. As air moves it carries its contents, like moisture and dust, along with it. Does air temperature effect air movement? We can perform an experiment to see if it does. (Spiral over light bulb)
Instructor divides student into an even number of groups. Half are given materials and instructions for the Air Mass experiment of balancing balloons. Half are given materials and instructions for the Air Movement experiment involving a paper spiral and light. Air Mass Experiment: Materials: 2 yardstick (meter sticks) 2 identical balloons 2 twist ties for the balloons 3 eight inch pieces of string 1 table or desk 1 weight (books will do) 3 small pieces of tape. Place a yardstick on the table under the the weight so that three-quarters of the stick protrudes out over the floor. Inflate the two balloons to approximately equal size and close them off with the twist ties. Tie knots in the ends of each string so you can slide them over the yardsticks. Bend the excess twist ties on the balloons into hooks so you can hook them to the strings. Use one string to hang the second yard stick from the first and hold it so it doesn't fall. Have team partners hang the other strings from the ends of the second yard stick then add the balloons. Carefully adjust the positions of the balloons until a balance is reached with the yardstick centered. Now apply tape to the strings so slippage will not effect the results. What do you hypothesize will happen if you let the air out of one balloon? Why? Now loosen the twist tie on one balloon and record what happens? Was your hypothesis correct? If yes, why? If no, why? Source:Ranger Rick's Wild About Weather. Air Movement Experiment: Materials: heavy paper or thin cardboard long piece of thread or string utility lamp with 100 watt bulb one small piece of tape Draw a spiral, as shown in the lesson, on the paper or cardboard. Cut around the lines of the spiral. Make a tiny hole in the center of the spiral and pass the thread through and tape it securely. What do you hypothesize will happen when you place the spiral above a heat source? Why? Hang the spiral above the utility light or above an active radiator in winter. Record what happens to the spiral. Was your team's hypothesis correct? If yes, why? If no, why not? Source: More Science Projects by Rogers If time allows, have the teams switch places and repeat the experiments without having to do any of the set up.
Summary: Students reform as a large group and report the result of their experiments with the prompting of their instructor and the instructional website. Instructor answers any question and addresses any problems the students have had with the exercise.
|8:44 AM|| Closure (7 min.)|
Remotivation: Congratulates the students on the success of their experiments and on their conclusions. Instructor summarizes the main points of the lesson. Closure: Instructor asks them to think about how the air an the weather are related and that the next lesson will cover the the water cycle. That is, how water becomes moisture in the air and then becomes water again. Instructor tells the class the lesson is over.