Sunday, January 29, 2012

Super Scientists

We had our class and school science fairs this week. Students were soooo excited to present and demonstrate their experiments to the class and their parents. They totally made a connection to how Beany, the main character in The Science Fair, felt when it was her turn to present!

 I was really impressed at how well they fielded questions and answered them. Our main focus was to connect our questions and experiments to real life - as in - WHY DOES THIS MATTER?

What will make ice melt faster, fresh room temperature water, salt water, or sugar water?
Result: regular water! Think about the ocean (salt water) - do you see it freezing easily? Her bar graphs show three trials, so her results were conclusive. Try it! Further investigation: Try it with different shape ice cubes

What material will best support a "parachute" to help it stay airborne the longest?

How does the composition (material) and weight of an object affect its ability to float or sink?
Result: objects made of wood, cardboard, and plastic floated, while objects made of glass sunk. Weight did not affect the object's ability to float. Try it!

Will the "Grow a Fish" grow faster in fresh or salt water?
Result: it grew much faster in fresh water. Try it!

Which boils faster, salt water or fresh (distilled) water?
Result: fresh water! Haven't you seen people put salt in the water, insisting that it boils faster? Not so! In fact, salt increases the boiling point so it must reach a higher temperature before boiling. Think about it - isn't the range of temperature of ocean water a lot smaller than the range of temperatures for fresh water (like in a pool)? We certainly wouldn't want our ocean boiling or freezing, so a higher boiling point and lower freezing point benefit animal and plant life in the ocean. Also, the water is deep and moves due to tides, so it is a lot less likely to freeze.

Which plant will grow taller, one in artificial light or one with sunlight?
Result: In this experiment, the plant on the left was grown using artificial light. It grew taller during the 8 days of the experiment because it had light all day long, while the plant on the right was exposed to sunlight only during daylight hours (it was cloudy on some days too). We noticed a difference in strength and color of the stems (the one with sunlight had darker, thicker stems and leaves), so we concluded that over the long term, artificial light can help plants grow faster because the plant receives more hours of light, but they do not necessarily grow better.

What makes objects (fruits) float, fresh water, salt water, sugar water, or oil in water?
Result: Objects floated best (if at all) in salt water. We noticed that the larger fruits tended to have more water and air inside them, so this may have affected their ability to float. For further investigation, she decided to try larger objects such as melons and pumpkins.

How will the amount of vinegar used affect the "strength" of the eruption?
Result: He measured the amount of liquid that came out of the homemade volcano into the pie pan underneath after adding different amounts of vinegar to the same amount of baking soda in each of three volcanoes. He found that more vinegar = larger eruption...to an extent! You can see this in his bar graph. Try it! Or try to do this on a computer with the Virtual Volcano!


How does density affect a liquid's ability to float?
Result: the less dense liquids floated to the top, while the more dense liquids sank. He made sure to use liquids that were different colors and he let them liquids settle without stirring them up so that results were easy to see. Try it!

How will make changing the amount of AlkaSeltzer affect the rocket's height?
Result: More AlkaSeltzer made the rocket go higher, but you have to make sure to use a sufficient amount of water, and make sure to control the amount of water since the amount of AlkaSeltzer is your variable. Try it!

How will the surface a ball is bounced on affect the height of its bounce?
Result: the tennis ball bounced highest on concrete, then wood, and least on carpeting. Because the carpeting did not have padding underneath it, the results were closer to the wood results. The ball bounced the highest on concrete. We thought about how this experiment might be useful to those who create sports fields and courts. There is a big difference between playing basketball on a hardwood floor than outside on concrete!

How will the type of liquid affect how much the Mentos fizzes?
Results: The Mentos fizzed the most in soda because of carbonation, and second most with apple juice because of its acidity. It barely fizzed at all in water, but the sugar in it did start to dissolve. (Her first idea was to put the Mentos in a closed container filled with a controlled amount of different liquids, but after some research, she realized it would be hard to measure the height the container would go. She did not put the Mentos in a closed container or shake it up, so she did not get the Mentos geyser effect.)


See my next post for the second set of experiments!