Ask Janice « GWCHE

Digestion: Teeth and Saliva

Kids too often do not properly chew their food.

This page contains information about chewing and the part of digestion that occurs in your mouth.

Chewing

Steps for Eating an apple:

1. Using your front teeth (incisors) , you bite off a piece of the apple. Incisor teeth are thinner and sharper than other teeth.

2. Once the food is in your mouth, you then chew it with your grinding teeth (molars). Molar teeth are wide with a rough surface on top. These teeth are in the back of your mouth and are used to grin food.

No matter how much you chew food, chewing cannot break the chemicals in food apart.

Digestion

Digestion is the breakdown of chemicals in food to forms the body can use.

Food Digestion starts in your mouth where saliva (spit) mixes with the food that you chew. It is important to chew your food well so that the saliva thoroughly mixes with the food.

Challenge:

Does saliva digest all kinds of food?

Discover For Yourself

Use small jars of differnt kinds of baby food, such a meats, fruits, and vegetables.

Disign your own technique for adding saliva to the food in each jar. One method might be place a spoon in your mouth so that its surface is covered with saliva, and then stir the food in one of the jars. Use a clean spoon for each test.

Please share your testing method and results. pictures would be wonderful.

Science Magic

Just like kids, I love magic, but I am never happy until I figure out how the trick is done. Equally as important, I don’t want to know the punch line in advance.

I like to try to figure out the trick that is behind the so called “magic.” I guess that is what makes science so exciting to me. It’s the never ceasing desire to explore and explain the magical mysteries of what is going on around us that keeps me challenged and very entertained.

As a teacher, I try to keep kids challenged. So instead of always giving answer to questions, I often answer with: “Let’s Find Out!”

Question: How can circles be magical?

Answer:

Let’s Find Out!

Have you ever made Möbius strips? If not, then you and your kids are in for wonderful surprises.

Remember: It is most important that the results of magical activities comes as a SURPRISE. So, be sure and do not reveal how the curvy circles are made. In fact, make them at a time when your children will not observe the process.

For instructions on how to make the three curvy circles needed for this Science Magic Activity as well as instructions for presenting the magic show,

Click Here, and then Search for Möbius Strips

photo source http://www.flickr.com/photos/barkbud/4537268923/

52239: Janice VanCleave&quot;s 203 Icy, Frosty, Cool and Wild Experiments

Janice VanCleave’s 203 Icy, Frosty, Cool and Wild Experiments

Barfing Flies

I hate flies for many reasons, including the fact that they are annoying. But more than being a nuisance, flies are nasty creatures that poop and regurgitate on food.

Yes! I am saying that flies deposit poop as well as vomit on the food they land on. They may not always poop on the food, but if the food is solid, they do vomit on it.

The vomit contains digestive chemicals that causes the chemicals in the food to start decomposing (breaking apart). The decomposed food can then dissolve in the liquid vomit.

Why all the vomiting? Flies do not have teeth to chew with. In fact, part of their mouthparts is a type of drinking tube called a proboscis. The picture compares a fly’s proboscis with a sponge. Both can soak up liquids.

After a fly has prepared its juicy meal by mixing vomit with the food, it then soaks up the juicy food with the end of its proboscis. The absorbed food is then sucked through the proboscus into its body where it is further digested and the nourishing parts are absorbed by the body.

Did you know that a fly can taste your food by standing on it? Yes, flies have taste sensors on their feet. If they like the food, they –well you know the drill. They have to prepare the food so that it is juicy enough to be sucked through their proboscis.

Flies are always swarming around rotting foods. Must be like going to a buffet with all the different partially decomposed foods. These juicy delights are easily to slup and the germs in this food are not a problem to the fly.

Not only do flies suck up germy foods, but they get it on the bristles of their feet. I wonder where th fly in the photo had its last meal? Looks like he is standing on a brown sugar treat prepared for someone—

Modeling the Moon's Rotation

Trying to visualize two of the Moon’s movement, rotation and revolution, can be difficult.

The diagram shows four locations of the Moon in its eastward revolution (orbiting) about the Earth. The red line on the small circles represents one position on the Moon.

Question: What parts of the Moon would an observer from Earth see if the Moon did not revolve on its axis?

Answer:

In the diagram, the small circles connected by the black line represent the movement of the Moon around the Earth if the Moon did not rotate on its axis.

In position 1, the red line points toward the East. If the Moon did not rotate on its axis, when it moved in its orbit around the Earth, the red line would always point toward the East.

Discover for Yourself

You could model this using anything to represent the Earth. Place your Earth model where you have enough room to walk around it. Letting each wall in the room represent a compass direction, stand so that you are facing the Earth Model as well as facing the east wall.

Now start your rotation around the Earth, but continue to face the east wall. Make note of the part of your body that faces the Earth in each of the four positions.

Position one–you face the Earth
Position two- your left side faces the Earth
Position three–your back side faces the Earth
Position four- your right side faces the Earth

Question: What parts of the Moon would an observer from Earth see if the Moon revolves once on its axis as it orbits the Earth?

Answer:In the diagram, the circles closest to the Earth represent the movement of the Moon around the Earth if the Moon Rotates ONCE during the orbit. Notice that the part of the Moon’s surface pointed to by the red line always faces the Earth.

Discover for Yourself

Repeat the previous activity, but this time you must continue facing the Earth Model. For each of the positions, which compass direction are you facing?

Using the information from this investigation, explain why an observer on Earth only sees one side of the Moon.

Moon’s Apparent Motion

Moon Movement

Kids as well as adults observe the daily movement of celestial bodies across the sky. We can depend on the Sun to daily rise in the east, move across the southern sky, and then set in the west. The Moon follows the same path that the Sun traces out.

Actually, neither the Sun nor the Moon move westward across the southern sky each day. Instead, this apparent daily movement of these celestial bodies is due to the eastward rotation of the Earth.

Investigation

Facts:

When you are not moving, stationary things around you remain at the same distance from you.
When you are moving, stationary objects in front of you appear to move toward you, while stationary things beside and/or behind you seem to move in the opposite direction of your motion.

1. While sitting in a stationary car, ask your kids to look at stationary objects, such as telephone poles outside the car. Note: You are an observers. Your position of observation is a stationary car.

Are the telephone poles stationary (not moving)? Explain your answer.

2. When the car is moving, again ask your kids to look at telephone poles. Note: You are an observers. Your position of observation is a moving car.

Are the telephone poles stationary (not moving)? Explain your answer.

3. The Earth is rotating toward the east. Note: You are an observe. Your position of observation is on the surface of the rotating Earth.

Neither the Moon nor the Sun is daily moving toward the west. Explain why these two celestial bodies appear to rise above the eastern horizon, move across the southern sky, and then set below the western horizon.

Astronomy for Every Kid: 101 Easy Experiment That Really Work

Gravity and Weight on Different Celestial Bodies

Weight of Box on Earth

I invite you to test science activities and experiments for me. If you are interested, you can contact me directly at ASKJANICE@aol.com

To give you a clue of what to expect, the following activity was field tested by Shay Arnold and her children. I emailed the activity with pictures to her. She and her children completed the activity and Shay let me know which parts worked best for each age as well as which parts were not clear. As a results of her input, I can now present to you a much better version of the activity. So let’s get started!

Did You Know?

A celestial body is any and all objects making up the universe. These include, planets, moons, suns, comets, stars, asteroids, etc….

Earth and its Moon are both celestial bodies.

Measuring the Earth’s Gravity

1. Your weight is the measure of the force of Earth’s gravity pulling you down.
NOTE: Down is the vertical direction toward the center of the Earth.

2. Weight on Earth, Fw = Force of Earth’s gravity, Fg
This means that when you stand on the bathroom scales, you are measuring the force of Earth’s gravity pulling you down .

Weight = Force of Gravity
Fw = Fg

Force of Gravity = Weight
Fg = Fw

The black box in Diagram A has a weight of one pound on Earth. This means that Earth’s force of gravity pulling the box down is equal to one pound.

Pound is a unit used to measure force.
Pound is a unit used to measure weight.

Measuring the Moon’s Gravity

Weight On the Moon

Let’s pretend that you can snap your fingers and send the box in Diagram A to the Moon.

Question: How much would the box weigh on the Moon?

REMEMBER: Weight is a measure of the force of gravity pulling an object down.

Answer: The gravity of the Earth’s Moon is about 1/6 as much as Earth’s gravity. This means that the weight of the box would be 1/6 of its weight on Earth. Thus the box’s weight is 1/6 pound.

Math Enrichment: 1/6 x 1 pound= ?? (Divide 1 by 6 = 0.167 pounds)

Investigation:

1. How much do you weigh on Earth?

Examples: Bret- 100 lbs. Bree and Brittan= 50 lbs.

2. How much is the force of Earth’s gravity pulling your body down?

Remember: Fg = Fw

Example:
1. Bret: weight = 100 lbs; Earths’s force of gravity pulling down on Bret = 100 lbs.
2. Bree and Brittan: weight = 50 lbs; force of gravity pulling down on Bree and Brittan= 50 lbs

3. If you could snap your finger and be on the Moon, how much would you weight?

Example: Bret= 16 lbs Bree/Brittan= 8 lbs

4. How much is the force of the Moon’s gravity pulling your body down?

Example:
Bret: weight =16 lbs; Moon’s force of gravity pulling down on Bret= 16 lbs

Bree/Brittan:= 8 lbs; Moon’s force of gravity pulling down on Bree and Brittan = 8 lbs

Did You Know?

I rode in NASA’s training and investigation plane commonly called “The Vomit Comet.” For information about my “weightless” investigation, click HERE.

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