Today’s experiment will demonstrate Newton’s Second Law of Motion.
Newton’s Second Law of Motion: Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).
SIMPLY: Pushing or pulling an object produces acceleration, a change in the speed of motion. Believe it or not, an accelertion can be a slowdown OR a speedup. The heavier the object, the more force it takes to make that object speed up or slow down. It takes more of your strength to push a bowling ball one foot than it does to push a marshmallow one foot.
In this video, an astronomer demonstrates Newton’s Second Law of Motion:
What You Need:
Pie Pan or Other Dish with Sides
Hot Chocolate Mix
3 Sizes of Marbles or Rocks
Put several spoonfuls of flour in the bottom of the pan and spread it out to make a level surface. Then sprinkle a thin layer of hot chocolate mix on top of the flour. Now hold one marble/rock above the surface of the flour and drop it. Do the same with the other two marbles/rocks. Now carefully lift each marble/rock out of the flour and look at the impact crater. Which marble/rock made the widest impact crater? Which one made the deepest impact crater?
Science Project Idea:
Do this experiment again. Use three different sizes of marbles. Marbles are great for this project because they are round which makes measuring the size of the impact crater easier. Remember that in a science experiment you want to test only one variable. In this experiment we only want to change the size/weight of the object that is falling. If we changed the shape of the object too, it would be hard to measure the difference in the impact craters.
While doing the experiment, pay close attention to how far away the marbles are from the surface of the flour before you let go of them. Use a rule to make sure you drop each marble from exactly one foot above the surface of the flour. Do the experiment three times using the same three objects. The three times you repeat the experiment are called trials. Make a chart to keep track of the results. After each trial measure the width of the impact crater made by each of the three marbles. Which marble makes the largest impact crater? Which marble makes the deepest impact crater? Why do you think so?
Plant parts like petals, leaves and stems have little holes called stomata – kind of like the pores in our skin. When stomata open, water escapes. When this happens the water is replaced by the plant absorbing water up from the roots into the stem and leaves and petals. As water evaporates from the leaves and petals more water is sucked up through the stem from the roots. This is called tranpiration…kind of like a person sucking on a straw.
What You Need:
White Flowers (Carnation, Queen Anne’s Lace)
Fill a vase with water. Add food coloring to the water. Collect or buy some white flowers. Make a fresh cut at the end of the flower stem and put the flowers in the water. Check on the flowers every hour. How are the petals changing?
Cohesion – When molecules of the same substance stick together. Transpiration – The loss of water from the parts of plants; petals, leaves, stems, flowers, etc. Absorb - To soak up. Evaporation – Water changing from a liquid to a vapor.
Even though air seems like nothing, it really is something. Gases like air, even though they are not visible to our eyes, are made up of molecules just like solid objects. These molecules are pulled toward the earth by gravity.
Earth is surrounded by a layer of air that is heavy. That layer of air exerts pressure on the surface of the earth, a lot of pressure. Our bodies are used to it so it doesn’t bother us. In fact, we are so used to it that what bothers us is when the air pressure is gone.
The higher you go in the atmosphere, the less air pressure there is because the “thickness” of the air is less the higher you go. That’s why airplanes have “pressurized” cabins. We can’t survive in too little air pressure.
What You Need:
Empty Water Bottle
As the bottle is filled with water the water pushes any air left in the bottle out. When you put the lid on no air can get in the botter either. Air on the outside of the bottle is pushing on it as well as the lid. The small holes in the bootle aren’t big enough for air to sneak in and increase the air pressure on the water…but when you open the cap more air can get in and press down on the water making it leak out the holes.
Here are some websites and books that will help you understand air pressure:
Air Pressure – The force that air exerts due to it’s weight. Even though air seems like nothing, it really is something. Gases like air, even though they are not visible to our eyes, are made up of molecules just like solid objects.
Everything in the universe is made of matter. Matter has mass (that means it is made up of something) and takes up space. Matteris made of atoms. Atoms are teeny, tiny – so tiny you can’t see them.
Some things are made up of just one kind of atom. These things are called elements. Some examples are oxygen, hydrogen & copper – you can look at a list of all of the known elements on a periodic table.
A single atom has three parts:
Electrons - a particle with a negative charge
Protons – a particle with a positive charge
Neutrons – a particle with no charge
The center of the atom is called the nucleus and the protons and neutrons are located there. The electrons are outside the nucleus. Sometimes two or more atoms come together to make a molecule. Water is an examply of a molecule. Water is made up of 2 hydrogen atoms and 1 oxygen atom.
What you might not know, is that there is a whole lot of empty space between the parts of an atom. When atoms come together to form molecules the molecules also have a lot of empty space. Atoms and molecules are made up mostly of empty space. You can prove that this is true:
What You Need:
Warm Tap Water
Fill the glass all the way to the top with warm tap water – the water should bulge at the top of the glass but not spill over. (Surface tension makes the water do that!) Now take a teaspoon and slowly add 1 teaspoon of powdered sugar to the water. Doesn’t it seem like 1 teaspoon of water should spill out of the glass when you add 1 teaspoon of powdered sugar? Does it? Add another teaspoon of powdered sugar. How many teaspoons of powdered sugar can you add before the glass of water finally overflows?
The powdered sugar moleculesdissolve into the water. The powdered sugar fills in the empty spaces between the water molecules. Even though it doesn’t seem like it…the glass of water is actually full of empty space!
Science Experiment Idea: Get 3 identical glasses. Fill the first glass with ice water (remove the cubes!), the second glass room temperature water and the third glass with hot tap water. Remember to fill the glasses up until the water bulges at the top. Now count how many teaspoons of powdered sugar you can add to each glass before the water start to spill out. Does the temperature of the water effect how much powdered sugar you can add?
Atoms - The smallest, most basic unit of matter.An atom is made up of a nucleus surrounded by electrons. Molecules - At least two atoms held together by a chemical bond. Matter – Has mass and takes up space. Periodic Table – A table or chart of the chemical elements. Mass - How much matter fits in a given space. Dissolve – When a solid comes apart and spreads out into a liquid…like kool aid in water.