Lesson Three/Four: Air power
Duration 1 hour for each lesson
Overview: Students will experience the power of air!
Vocabulary: Air, power, force, friction
Objectives: Students understand that air has power and can be used to do work. Air makes our lives easier. Students will make an air cannon and a hover craft.
Materials: 20oz soda bottles, electrical tape, balloons, CDs, sport bottle drink lids, hot glue gun/glue, candle, small puff balls
Resources: Youtube hovercraft video
The Lessons:
- Ask students what they have previously learned about air. Ask them what we saw the students in the "Magic School Bus" video do with air.
- Tell them you are going to make an air cannon! The challenge will be if students can blow out a candle using the air cannon.
- Making the cannon: Cut off the top of a soda bottle (just above the top of the label) using a box cutter. Tie a knot in the neck of a balloon. Cut off the very tip of the top of the balloon. Open the balloon and stretch it over the larger opening of the bottle top you cut earlier. Tape the balloon secure. You should be able and pull the knot of the balloon back, then release, to shoot a blast of air out the mouth of the bottle.
- Allow students to play with their air cannons (move puff balls, pieces of paper, etc). Let the students come one at a time to try and put out a candle.
- ASK HOW IT WORKS: Students should connect that air has volume concept here. Pulling the balloon back brings air into the bottle. When they let go air is quickly pushed out of the bottle creating a blast of air. This air can be used to do work.
- BREAK HERE TO MAKE TWO LESSONS OR CONTINUE FOR A TWO HOUR LESSON
- Play the hovercraft video
- Ask students to rub their hands together. What do they feel? (HEAT). Explain the concept of friction. Guide students through questions and discussion to realize that friction is what keeps items from gliding around on surfaces.
- How can we overcome friction? AIR!
- Help each student to make a hovercraft
- Making the hovercraft: Hot glue the sport bottle top on a CD such as it covers the central hole. Inflate a balloon and attach it to the bottle top (the bottle top should be in the down closed position such that air cannot be released from the balloon). Let the students place their hovercraft on the floor and open the top. Air should travel down the central hole to under the CD. This creates a thin layer of air that overcomes the force of friction and allows the CD to glide across the floor.
- ASK HOW IT WORKS: Students should connect the concept of friction and that air is reducing the friction and allowing the CD to glide.
Homework: Ask the students if the hovercraft will work on water. Have them try it at home in a large bin or bathtub. Ask them to record a video with their parent's phone and send to the class group chat.
Citations:
Lesson Five/Six: (Liquid) Water Properties
Duration 1 hour for each lesson
Overview: Students will learn the properties of water. Focus on surface tension and density (i.e. sink or float)
Vocabulary: Liquid, force, surface tension, weight, volume, density, sink, float, peel
Objectives: Students discover the properties of water and can explain the meaning of surface tension and density. Students can explain why some things float and other things sink.
Materials: Coins, water, pipettes, cups, large tub, various items, cans of soda (some diet and some regular), multiple oranges, LOTS OF TOWELS
Resources: Youtube Videos of creatures using surface tension "Basilisk lizard runs on water, rate my science" "water striders" etc.
The Lesson:
- Ask students what they have learned so far. Review the major properties of air. Ask what state of matter air represents (GAS!). Then ask what state water represents (LIQUID!).
- Try to get the students talking about what things they see on water and what things they see underwater. Get them thinking about why some things sink and some things float.
- Ask them "Did you know water has skin?" Introduce the concept of surface tension. Show some photos of phenomena like a swimmer breaking through the surface of water. It should look like a 'skin' is stretching over them.
- Fill a glass with water. Ask them how many coins they think can be added to the glass until the water spills over the side. Let each student write down their guess for how many coins. Drop in coins one by one. You should be able to add more than 20 coins depending on their size/size of the glass. After completing this show a time-lapse video of the same experiment (there are many options of this online). Reiterate the concept of surface tension.
- Ask students if they know of any animals that take advantage of surface tension. Show videos of animals using surface tension to move on water. (Basilisk lizard, water striders, etc)
- Now ask the students how many drops of water can fit on one coin. Put the students in groups of 3-4. Have the groups write down their guess for how many drops. Let the students take turns adding drops of water to the top of the coin using a pipette. Use this as opportunity to present proper pipette techniques (important for students that will continue in science).
- Have each group report their findings. Write the results for each group on the board. Calculate the mean, median, and mode of the data. Ask students why it is important to do the experiment more than once. The goal here is to introduce the concepts of experimental error and variation.
- BREAK HERE TO MAKE TWO LESSONS OR CONTINUE FOR A TWO HOUR LESSON
- This section is to introduce the concept of density. Ask students what things are able to float on water. Make a list on the board of things that sink and things that float. Write the equation for density on the board. Use this as an opportunity to review the concepts of weight and volume from the lessons about air.
- Ask students if they think an orange will sink or float? Make tallies on the board showing how many student say it will float and how many say it will sink. Put the orange in the water. IT FLOATS! Now ask the students what you could do to the orange to make it sink. They might suggest adding weight etc. Add the complexity that they can't add anything to the orange. Hopefully a student will have the idea to peel the orange. The peeled orange will sink. Discuss what characteristic of the orange peeling the orange changes (density).
- Do a sink/float discovery activity. Have the students get into the same groups they used for the drops on a coin activity. Give each group a paper on which they can write the name of an item, as well as if the item sunk or floated when placed in water.
- Each group of students should have their own tub of water and many random items that they collected from home (given as previous assignment) or provided by the teacher. Have the groups test all of their materials. If students are older also have them weigh each item and approximate how many cubic centimeters the object occupies (volume). If students are really intrigued, ask them to estimate the density of water based on their estimated densities of items that either sank or floated.
- Do a demonstration with various soda cans. Ask the students if they think a can of soda will sink or float. Have them discuss in their groups what they think and why. Put a large clear tub on a table in the front of the class. Place the cans in one at at time. The regular soda cans should sink while the diet soda cans float/sink only slightly.
- Ask the students if they see a pattern in which can sink and which ones don't. Have them spend time discussing what patterns they see (eventually point out regular sink and diet float if they haven't said it yet). Ask them why regular cola sinks but diet doesn't. Have them say theories as long as it takes for one of them to realize regular cola has sugar, whereas diet doesn't. This would increase the weight but the volume of the can remains the same. Thus regular soda has a greater density than diet soda. This density difference spans the density of water, so they display different behaviors.
Homework: Ask students to experiment at home with various liquids in their kitchen (vinegar, oil, soy sauce, etc). Which ones are more dense than water and which ones are less dense than water? How do they know? Challenge them to make a glass have at least three distinct layers of liquid.
note: \(density\ =\ \frac{mass}{volume}\)
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Lesson Seven: Super Solids! Magnetic Force
Duration 1 hour