I am finally back to finish giving some more experiments on water called Buoyancy.I am skipping Interplay of forces and Inertia because I think I already gave them to you. I will add them at the end of the week when I check it out and make sure just in case. For now I will be giving you experiments on sound, light, and then some on illusions when I check it out also. By my notes I can't tell well enough.
The first experiment is called Loss of weight.Tie a stone by means of a thread to a spring balance and note its weight.Does it in fact alter if you hang the stone in a jar of water?
If you lift up a large stone under the water when you are bathing you will be surprised at first by its apparently low weight. But if you lift it out of the water, you will see how heavy it actually is. In fact an object immersed in a liquid (or in a gas) loses weight. This is particularly obvious with a floating object. Look at the next experiment.
The next experiment is called Archimedes' principle. Fill a container up to the brim with water and weigh it. Then place a block of wood on the water, and some of the liquid will spill out. Weigh again, to find out if the weight has altered.
The weight remains the same. The water spilled out of the container weighs exactly the same as the whole block of wood. The famous mathematician Archimedes discovered in about 250 BC that a body immersed in a liquid loses as much weight as the weight of liquid displaced by it. This apparent loss of weight is called buoyancy.
The third experiment is called Water puzzle. Lay a small tray or a wooden ruler over a six sided pencil and place n it two jars filled with water balanced as on a pair of scales. What happens if you immerse a cork into the water in one jar. While placing a cork of the same size on the water in the other jar? Does one side of the balance become heavier, and if so, which side?
The balance leans to the side where you immerse the cork in the jar. That is, this side increases in weight by exactly as much as the weight of water displaced by the cork. The other jar only becomes as much heavier as the weight of the cork itself.
The fourth experiment is called Mysterious water level. Place a half-dollar, ten new pence, or a penny in a match box and float it in a glass of water. Mark the level of the water on the side of the glass. Will it rise or fall if you take the coin from the box and lower it into the water? Just think about it first!
The water level falls. Since the coin is almost ten times heavier than water, the box containing the coin also displaces, because of its larger volume, ten times more water than the coin alone. This takes up, in spite of its greater weight, only a small volume and so displaces only a small amount of water.
The fifth experiment is called Volcano under water. Fill a small bottle full of hot water and color it with ink. Lower the bottle by means of a string into a preserving jar containing cold water. A coloured cloud, which spreads to the surface of the water, rises upwards out of the small bottle like a volcano.
Hot water occupies a greater volume than cold because the space between the water particles is increased on heating. It is, therefore, lighter and experiences buoyancy. After some time the warm and cold water mix and the ink is evenly distributed.
The sixth experiment is called Suspending an egg. Half fill a jar with water and dissolve plenty of salt in it. Now add as much water again, pouring carefully over a spoon so that the two liquids do not mix. An egg placed in the jar remains suspended as though bewitched in the middle.
Since the egg is heavier than tap water, but lighter than salt water, it sinks only to the middle of the jar and floats on the salt water. You can use a raw potato instead of the egg. Cut a roundish 'magic fish' from it, and make fins and eyes from coloured cellophane.
The seventh experiment is called Dance of the moth balls. Add some vinegar and bicarbonate of soda to some water in a jar. Toss several moth balls, which you can colour beforehand with a crayon to make the experiment more fun, into the bubbling bath. After a time the balls dance merrily up and down. Since the moth balls are a little heavier than water, they sink to the bottom of the jar. The carbon dioxide freed by the chemical reaction between vinegar and surface of the water. There the bubbles escape, the balls sink again, and the performance is repeated.
The eighth experiment is called Pearl diver. Stick a match about one-tenth of an inch deep into a coloured plastic bead and shorten it so that its end floats exactly on the surface of the water when the bead is placed in a milk bottle full of water. Close this with a plastic cap. By changing the pressure on the cap, the bead can be made to rise and fall as though bewitched. Plastic is only a little heavier than water. The match and the air in the hole of the bead give it just enough buoyancy for it to float. The pressure of the finger is conducted through the water and compresses the air in the bead. Thus it no longer has sufficient buoyancy and sinks.
The ninth experiment is called The yellow submarine. Cut a small boat out of fresh orange peel and make portholes on it with a ballpoint pen. Place the boat in a bottle filled with water and close it with a plastic cap. If you press on the cap, the boat rises and falls according to the strength of the pressure. Minute air bubbles in the porous fruit peel make it float. By the pressure of the finger, which is transmitted through the water, the bubbles are slightly compressed, so their buoyancy is less, and the boat goes to diving stations. Since the yellow of the peel is heavier than the white, the submarine floats horizontally.
You can accompany the submarine by several 'frogmen'. Simply toss broken-off match heads with it into the bottle. They float, because air is also contained in water pressure, the match heads dive deeper too.
The next item for Grandma to give you with this day is a book called Three Names identifying changes in Geography by Patricia MacLachlan and Illustrated by Alexander Pertzoff (HarperCollins 1991). This book was found out about by Grandma in her Book (4).
From his great-grandfather, the narrator learns what it was like to live and go to school on the prairie many years ago. Three Names, great-grandfather's dog, goes to the one-room schoolhouse each day with the children. Like them, he notes the changing seasons, enjoys the camaraderie of the small classroom (where pupils teach as well as learn), and spends the summer waiting eagerly for school to begin again.
As You Read
Use a chalkboard chart like the one below to guide comprehension of likenesses and differences between the great-grandfather's schooldays and those of your (children).
Encourage (the children) to respond to the story by telling (1) what they would like or dislike about attending a school like the one described, and (2) what activities from great-grandfather's school days are similar to one in their own school, for example, playing with friends, having special snacks, giving holiday parties, and helping one another learn."
Extending Geography Skills:
Link to YouTube Topographical Maps for this part. After learning "what the map tells about the altitude, land forms, water bodies, and so forth of this region, explain to (the children) that a topographical map shows a "bird's eye view" of a region," if the videos do not."Invite (the children) to review with you the story and the illustrations to get an up-close view, or Three Name's "dog's-eye view," of the same region. As (the children) discuss the pictures and note descriptive phrases, write their observations on the chalkboard (for example, "flat land," "ponds (sloughs)," "cold winters"). Distribute strips of paper and suggest that (the children) choose and illustrate some of the chalkboard phrases.
Place the strips to the right of the map under the heading The Prairie Up Close. Extend the activity by inviting (the children) to suggest how the prairie has changed since great-grandfather's day (growth of cities, building of highways, more people, etc.).
Some (children) may enjoy writing a description or drawing and captioning a picture that tells what a modern-day Three Names might see if he were on his way to school on the prairie today. Place the descriptions and drawings in a folder near the" schooling area for the children to read and remember.
Tornado Time-Review page 26 of the story, which tells about a tornado and its effects. Invite interested (children) to research tornadoes to find out how they are formed and where they usually occur. After (the children) have presented their findings ...discuss "threatening" weather that typically occurs in your region... and how people today try to protect themselves--as the students in the story do--in these situations.
Each One Teach One-Discuss why a one-room schoolhouse was sufficient for many communities in great-grandfather's time." Discuss how older students may have helped younger students learn in those times or did they really do any of it. Discuss how some school students today help others. Then discuss how older siblings in your home may be helping the younger ones. If not how you as parents help. Then discuss how schools and homes are now do a lot of their learning by programs we have set up to learn by in their homes or a classroom now and how they feel about this type of learning and if it will be effective in your opinions. Explain why or why not.