Exploratorium

toc =Proposal=



You are way behind schedule.

=4/19/12 - Choose topic= Topic: Fluids

=5/12/12 - Recruit assistants= Assistants - Ben Weiss, Jake Greenstein, Ryan Luo

=5/18/12 - Proposal= The demos I will be doing are as follows: first to demonstrate pressure I will do the stick and paper demo; then to show buoyancy and density I'll do the coke/diet coke demo; then I will move on to Archimedes' Principle and do the weight in water demo; and last I'll do the take away demo of the Cartesian diver.

=Demos=

Where is the paper and stick demo?


 * Coke/Diet Coke**

Materials: Transparent tank (i.e. fish bowl) Water Diet soda can Regular soda can

Procedure: Fill the transparent tank ¾ full with water. Place the diet and regular soda cans, and observe which ones sink and which ones float.

Concepts: Density




 * Weight** **in water**

Materials: Stand 2 beakers Water Hanging mass scale Bucket that can hang off scale and also has hook on bottom Hanging Mass

Procedure: Hang the bucket onto the scale that will be attached to the stand, and hang the mass on the bucket. Fill a beaker until it almost overflows and place the other beaker in a place that will be able to catch the overflow from the filled beaker. Weight the dry mass of the bucket and mass first, and then slowly lower the hanging mass into the beaker filled with water until the mass becomes buoyant. The scale should record the mass of the hanging objects to be lower than what it should be after lowering the objects into the water. If you pour the water that is displaced into the bucket, the measure should go back to what the original reading was.

Concept: Archimedes Principle




 * Cartesian Diver**

Materials: . one 2 liter soda bottle . one medicine dropper . one glass or beaker

Procedure:
 * 1) Fill a glass with water
 * 2) Put the medicine dropper into the glass and suck enough water into the dropper so that when you let it go, it is barely floating
 * 3) Only the black rubber part should be above the water
 * 4) Once the medicine dropper has enough water, fill the soda bottle with water
 * 5) Put the medicine dropper into the soda bottle and close the bottle tightly.
 * 6) Squeeze the soda bottle. Observe what happens to the medicine dropper
 * 7) It should move down to the bottom.
 * 8) Let go of the soda bottle slowly. Observe what happens to the medicine dropper.
 * 9) It should move back towards the top of the bottle.



Concepts: Fluids- a substance that takes the shape of its container; the water is a fluid

Density- mass per unit of volume

Pressure- force experienced by an object all over its area; the pressure on the medicine dropper from the water causes it to stay where it is; squeezing the soda bottle increases the pressure and makes it move!

Buoyancy- the ability to float; occurs when the average density of an object is less than the density of the fluid it is in.

=Script=


 * Coke/Diet Coke**

If you’ve ever thrown a rock in a lake or ocean, you’ve noticed it sinks. If you’ve ever blown bubbles under water, you’ve noticed that they rise up. The reason these happen is because of density. Density is one way we can describe different materials around us. Density is the idea that for a specific volume, there can be a different amount of mass. If you fill up one cup with marshmallows, and another with chocolate chips, the one with chocolate chips is heavier. They both take up the same amount of space- one cup- but the chocolate chips have more mass. If an object has more mass for a given space, it is more dense, and an object with less mass for a given space is less dense. When we combine different things with different densities, they will rearrange themselves in order of density. The densest more dense will go to the bottom, while the least dense will rise to the top. This is why a rock, which is denser than water, will sink while air, which is less dense than water, will rise up. We can test this out. Regular soda is made with mostly air bubbles of gas, water and sugar, while Diet is made with air bubbles of gas , water and artificial sweetener. Sugar and artificial sweetener are not the same density. Whichever one is denser will sink farther. Raise your hand if you think the Diet soda is denser. Raise you hand if you think the Regular soda is denser. The regular soda sank, while the diet soda floats. That’s because the sugar in the regular soda is a lot denser than water, making the whole soda denser, and making it sink. The artificial sweetener in the Diet soda is not as dense, and the water is denser than it, so the can of soda rises to the top.
 * Perform Experiment*


 * Weight in Water**

Have any of you ever taken a bath? If you have, you may have noticed how the water level rises whenever you get in the tub. You may also have noticed that the water level increases more when more mass is added to the tub. Why does this happen? According to Archimedes, water usually provides somewhat of a support for any object that is placed in the water. When you place your foot in the water, you exert a force downwards, and the water exerts a force upwards. The upward force is called the buoyant force, and it is what causes the water level to rise. Archimedes figured out that the amount of water being moved is equal to the mass of the object that was placed in the water. This can be shown through a simple experiment. The language here is both incorrect and too sophisticated. As you can see on the scale, the mass of the object is less than the original mass of the object in the water. However, if you pour the water back into the bucket, the original weight is restored.
 * Perform Experiment**


 * Cartesian Diver**

Hi everyone! My name’s Ben and welcome to my demo. This activity I’m going to show you today is called the Cartesian Diver and it’s really cool! Just like all the other demos you’ve seen today from our group, this involves fluids and is really easy to do at home. Let me show you how this works.

So before I begin, let me explain what the point of this is. By doing this demo, you’re showing that the more dense (or the more mass the object has in it) an object is the less buoyant (or floatable) it becomes. We’re increasing and then decreasing the mass of a diver to make it sink and then float back up in water

First off, you need to assemble the materials to do this demo. The things you need are: one 500 mL water bottle (just your typical Poland Spring or Dasani bottle), a medicine dropper (which is going to be the diver) and a glass beaker let's use plastic cups, which you can have filled with water ahead of time. You only need 4 or so. The next step is to fill up the glass beaker with tap water.

From here, you need to prep the dropper to be your diver. To do this, you need to start filling it with water from the beaker. You should have enough water in the dropper that when you let it go into the beaker, only the black bulb is above the water. Once you’ve done this, the diver is ready to be put into action.

The next step is to fill the water bottle with water (if it already isn’t full). Then, you need to insert the diver into the bottle and let it go into the water. After this, you need to close the bottle tightly. You should be noticing that the diver is floating in the water.

Now comes the cool part: take the water bottle in your hands and squeeze!

[Squeeze the water bottle]

What do you see? [Let people answer the question] You should be noticing that the diver is actually sinking in the water. Why do you think this is happening [Let people answer the question].

It’s actually happening because the diver is becoming denser. By putting pressure on the water bottle, we’re forcing more water into the diver. Doing this increases the amount of mass within its volume, which makes it denser. This has the effect of making the diver less buoyant or able to float.

Let’s see what happens when you stop squeezing.

[Slowly remove hands from the bottle]

Did you all see how the water bottle moved back up the bottle? Because we’re not squeezing anymore, the water that had entered the diver is released. By doing this, we’re decreasing the mass in the volume of the diver and making it less dense. By doing this, we’re making the diver more buoyant so it floats more. Please go through and fix some of the language in this section. Some may be too complicated. Other parts you have simplified so much that the concepts are not accurate.

These concepts of density and buoyancy affect a lot of objects in the real world. Why do think a brick sinks when you put into water? It’s because the brick is more dense and less buoyant. The opposite is true for a beach ball; it’s a lot less dense and will therefore float above water. If you want to continue checking this out outside of the Exploratorium, buy these materials at your nearest supermarket and try it out for yourself. I would definitely not suggest dropping a brick into your pool!

That concludes my demo! Thanks so much for stopping by and I hope you guys enjoy the rest of the Exploratorium!

=**Final Script**=


 * Coke/Diet Coke**

If you’ve ever thrown a rock in a lake or ocean, you’ve noticed it sinks. If you’ve ever blown bubbles under water, you’ve noticed that they rise up. The reason these happen is because of density. Density is one way we can describe different materials around us. Density is the idea that for a specific volume, there can be a different amount of mass. If you fill up one cup with marshmallows, and another with chocolate chips, the one with chocolate chips is heavier. They both take up the same amount of space- one cup- but the chocolate chips have more mass. If an object has more mass for a given space, it is more dense, and an object with less mass for a given space is less dense. When we combine different things with different densities, they will rearrange themselves in order of density. The more dense will go to the bottom, while the least dense will rise to the top. This is why a rock, which is denser than water, will sink while air, which is less dense than water, will rise up. We can test this out. Regular soda is made with mostly bubbles of gas, water and sugar, while Diet is made with bubbles of gas, water and artificial sweetener. Sugar and artificial sweetener are not the same density. Whichever one is denser will sink farther. Raise your hand if you think the Diet soda is denser. Raise you hand if you think the Regular soda is denser. The regular soda sank, while the diet soda floats. That’s because the sugar in the regular soda is a lot more dense than water, making the whole soda more dense, and making it sink. The artificial sweetener in the Diet soda is not as dense, and the water is more dense than it, so the can of soda rises to the top.
 * Perform Experiment*


 * Weight in Water**

Have any of you ever taken a bath? If you have, you may have noticed how the water level rises whenever you get in the tub. You may also have noticed that the water level increases more when more mass is added to the tub. Why does this happen?

Actually, when you place your foot in the water you are pushing down on the water but at the same time the water pushes back up on you. This is called the buoyant force. So when you are submerged in water, because the water is pushing up on you, you actually weigh less. Let's take a look at a hanging mass.


 * Perform Experiment**
 * hang mass on scale in the air and have them take note of the weight*
 * then submerge the mass into water and have them take note of the weight*

As you can see on the scale, when the mass is submerged in water, because the water pushes up on the mass, it weighs less than when it is just hanging in the air.


 * Cartesian Diver**

Hi everyone! My name’s Ben and welcome to my demo. This activity I’m going to show you today is called the Cartesian Diver and it’s really cool! Just like all the other demos you’ve seen today from our group, this involves fluids and is really easy to do at home. Let me show you how this works.

So before I begin, let me explain what the point of this is. By doing this demo, you’re showing that the more dense (or the more mass the object has in it) an object is the less buoyant (or floatable) it becomes. We’re increasing and then decreasing the mass of a diver to make it sink and then float back up in water

First off, you need to assemble the materials to do this demo. The things you need are: one 500 mL water bottle (just your typical Poland Spring or Dasani bottle), a dropper (which is going to be the diver) and plastic cups. The next step is to fill up the cups with tap water.

From here, you need to prep the dropper to be your diver. To do this, you need to start filling it with water from the beaker. You should have enough water in the dropper that when you let it go into the beaker, only the black bulb is above the water. Once you’ve done this, the diver is ready to be put into action.

The next step is to fill the water bottle with water (if it already isn’t full). Then, you need to insert the diver into the bottle and let it go into the water. After this, you need to close the bottle tightly. You should be noticing that the diver is floating in the water.

Now comes the cool part: take the water bottle in your hands and squeeze!

[Squeeze the water bottle]

What do you see? [Let people answer the question] You should be noticing that the diver is actually sinking in the water. Why do you think this is happening [Let people answer the question].

It’s actually happening because the diver is becoming more dense. By putting pressure on the water bottle, we’re forcing more water into the diver. Doing this increases the amount of mass within its volume, which makes it more. This has the effect of making the diver less buoyant or able to float, so it sinks.

Let’s see what happens when you stop squeezing.

[Slowly remove hands from the bottle]

Did you all see how the water bottle moved back up the bottle? Because we’re not squeezing anymore, the water that had entered the diver is released. By doing this, we’re decreasing the mass in the volume of the diver and making it less dense. By doing this, we’re making the diver more buoyant so it floats more.

These concepts of density and buoyancy affect a lot of objects in the real world. Why do think a brick sinks when you put into water? It’s because the brick is more dense and less buoyant. The opposite is true for a beach ball; it’s a lot less dense and will therefore float above water. If you want to continue checking this out outside of the Exploratorium, buy these materials at your nearest supermarket and try it out for yourself. I would definitely not suggest dropping a brick into your pool!

That concludes my demo! Thanks so much for stopping by and I hope you guys enjoy the rest of the Exploratorium!