Fraser (12) asks. What are the important parts of aerodynamics?

Fraser

Many thank for the question. To help you answer it I suggest you make your own paper aeroplane. Investigating the flight of the plane will be the beginning of your investigations of aerodynamics.

Below is a plan (Using a sheet of A$ paper) that you can use to make a plane and begin the investigation.

Once you have made the plane, try flying it. Think of the things that make it fly. How far, for example can you make your plane fly. Does it depend on how hard you throw it?  That is the THRUST that enables it to fly and is an important element of AERODYNAMICS.

I shall pass you over to my friends, who will no doubt ask you more questions. (They will need some time to answer so please come back a bit later)

Here is what they said.

Hello Aster.

I think a paper aeroplane is a good start to investigate aerodynamics. As the Science Master said …..how far the aeroplane flies with a simple push is a good way to investigate one of the main aerodynamic properties associated with any that flies. This is Thrust .

The other major aerodynamic considerations, in addition to Thrust are Gravity, Lift, Drag and Air Drag.

 

Piper Astra (10) asks Why do we have to die ?

Thank you for your question Piper. I shall ask my friends to contribute later.

Humans and animals die because our bodies stop reproducing cells – cells are the building blocks of our body. Amazingly about 40 billion of them die every day…and our body replaces them. However as we get older the replacement process is reduced and eventually it stops, so we die.

However for trees this does not happen, the replacement process continues and the tree keeps on living. Some trees that you might see around you are hundreds of years old.

These are my early thoughts on your interesting question. My friends will add to this when they are ready.

Hugo (7) asked – “Is the world magnetic?”

Hugo, a great question. I think the world is magnetic but I am not sure how we can find out if it is. Let me ask my friends. They should be able to give me an answer in a few hours time. I think it is something to do with compasses.

Hugo, I think you will need some equipment ……. a small bar magnet and a square of polystyrene or woo. This will mean that you can float the magnet on some water.

 

Clara (7) asked – How are all sorts of jewels made?

Clara, thank you for your question. I will ask you a question “What do you think jewels are made of?”  this would help in deciding how jewels are made.

Are jewels made from hard or soft things? Are jewels made of metal or some other material?

Wow…I used the word “material”. What do you think that means?

Material is a word to describe what things are made of. We recognise a material by its properties. Is it hard, soft, bendy, runny, smelly, strong, brittle?

I asked a friend about your question. Here are her thoughts.

Thanks for that.

Clara, it might be difficult for you to examine the properties of the diamond. It is made from a material that is very, very hard. Maybe you could investigate its hardness ….how do you think you could do that?

Is the diamond held in a metal. There are lots of different metals all of which have different properties. Can you find some metals that are different from the metal that the diamond might be held in.

Let me know in the comment box below.

Jose (10) asks –What is Plasma?

Jose, thanks for your question. I gave it to my team. Here is their answer…..

 

Thanks team, I liked your answer. Jose…can you understand. A gas, solid or liquid consists of small particles called molecules. A drop of water contains thousands of water molecules. Each molecule consists of two Hydrogen atoms and one Oxygen atom. Each atom consists of a core of a number of positively charged particles called ‘protons‘ which are surrounded by an equal number of negatively charged particles called ‘electrons‘. If we manage to remove an electron from the water molecule …it leaves the water molecule with one less negatively charged electron so it becomes positively charged. It forms a Plasma.

Cheyanne (11) asked “What is the total charge of 7 electrons”

Cheyanne

I am a little confused  by your question. I asked my team for an answer……and here it was

 

Thanks team. I would like to add a little bit more to your answer

Firstly the electron is a very, very small particle, it has a radius of 0nly 2.8×1015 m.   It is very, very small. That is an unimaginable small size.  Associated with this very small particle is an actual , very small electrical charge of about  1.6x 1019 volt (V).

So in reality when you are talking about the total charge of seven electrons you are only talking about  7 x 1.6x 1019 volt (V).

Sorry for this answer. I think it complicates things …stick to what my team member says. In reality when you are talking about the charges on seven electrons as 7- you are talking about the total charge that about  7 x 1.6 x 1019 electrons will give you .

Unknown (7) asked “What is carbon dioxide?”

Firstly….my apologies…I lost your name.I can remember the question but not the name.

 

I asked my team to try to answer this important question

We all produce Carbon Dioxide when we breathe …..it is however not as much as when the things burnt above produce. As you get older you will learn about how Carbon Dioxide affects the weather on our planet. You will also begin to see why all plants and trees are important in controlling the amount of carbon dioxide in our atmosphere.

Many thanks for asking your question.

Dhanashree (13) asks “Why is sound a longitudinal wave?”

Dhanashree, thank you for the question. I asked my team about the question and they arrived at the following answer….which I was not happy with …….

There are two types of ways in which waves manage to travel ……. Longitudinal and Transverse. I can see the way the waves they develop BUT need time to think about how to explain them. Longitudinal waves travel along straight lines away from the source …  I am trying to understand how the particles associated with the travelling disturbance (sound) travel in each of these ways.

How do the particles of air (in longitudinal movement) make further particles of air move in the same way…if they are doing forward and back vibrations? The vibrating air particles (or particles of any gas) must be moving forwards as well as moving back and …thus moving the wave forward.

So …to answer your question …..sound is created by things vibrating, the drum skin vibrates, up and down when it is hit…….the air above the drum skin follows this vibration, and the air next to the vibrating air , starts to vibrate and so on. This is your longitudinal vibration.

With Transverse vibrations the particles move up and down. Like waves …which stay in the same place.  More thinking about this later.

Sam (13) asked “What are the building blocks of cells? And does it vary for each cell?”

Up-dated  24/10/2019

Thank you for your question Sam. As usual I put it to a member of my team. Lets see what they say and then, maybe, I can add to it.

Thank you for that team. Cells are obviously very, very important. We, and all, living things are all made up of them. But what about the cells themselves …what are they made of ? A little research shows that all cells contain  proteins, lipids, carbohydrates and nucleic acids. Let’s look at the role of each of these groups of compounds.

Proteins are all important (they are made of things called amino acids BUT enough of that). Proteins have important roles in cells. They provide the cell with energy, they fight infections they help move other components  around the cell.

Lipids are basically fats and therefore are a source of energy. The proteins will access the lipids to help them in their tasks and the Carbohydrates are another source of energy

Nucleic acids are better known as amino acids that make up  RNA and DNA structures. These are probably the most important, ………no I am wrong, the nucleic acid component of the cell needs all the other components to survive. They will not last long if left alone. The nucleic acids are the messengers of the cells. In simple terms they have, in their structure , the message that enables the construction of a living thing (animal, plant) from the activity of the rest of the cell. You could say they are the managers.

A little addition ……. what is an amino acid? Firstly as an acid it contains the -COOH group of atoms. CH3COOH is a familiar acid

Shown here in its structural form

known as acetic acid (vinegar).

Amino acids basically contain NH2 groups instead of CH3 . One of the simplest is glycine.

Proteins also (in some cases) act as catalysts (something that enables a reaction to occur. In these situations they are called enzymes.

I really hope this is helpful. Thanks for the question.

Taj (13) asks ” “What makes some metals more reactive than others?”

Many thanks for that introduction to Taj’s question. the images for the three metals show the electrons in ‘shells’ around the core metal atom.  Taj, you may be interested to know that the electron was discovered in 1897 by Thomson and the arrangement of electrons in shells around the nucleus by Neils Bohr in the 1920’s ….only 100 years ago.

Look at the ‘shells’ …the first one near the nucleus of all the metal atoms contains 2 electrons, the second shell  contains 8 electrons, the third shell contains 18 electrons , the fourth shell contains 32 electrons (which are subdivided into three levels).

It is the outermost shell that is the important one when it comes to chemical activity. If the shell is full (has its load of electrons) the atom is unreactive (noble gases). If the shell is not full …the atom is reactive and the reactivity seems to be linked to how empty the outermost shell is and how close the shell is to the atomic nucleus.

Think about these rules when you look again at the sodium, copper and gold atoms.

Thanks for the question.