Amasidda (?) asked “Give one reason to prove that light is form of energy”

 

Then Amasidda you might be able to answer the question yourself.  Think about what all forms of energy – electric (electricity), light, heat (thermal), movement (kinetic), nuclear, chemical, sound, gravitational, can do. Can they all in some way do work? Can they all be converted from one from one form of energy to another?

What do you think ‘work’ is? Let me know in the comment box below.

“How does speed affect the energy of motion during a collision?” asked Damián Muñoz (9)

Thank you for your question Damian. I asked my friends about it and they had the following thoughts.


Sorry Damian it doesn’t really answer the question you asked. They have just presented you with more questions.
Let’s look at what they said.

Firstly energy is about work. The Energy or Work associated with a moving car is its movement. This type of energy is called Kinetic Energy. We could change the car’s Kinetic Energy by making the slope steeper (move the slope up a rung). It will make it go faster.

How do we measure the energy it is gaining as it moves faster and faster down the slope? Yes it does go faster while it is on the slope (we say that it is accelerating). Remember it starts with no energy at all (not moving). When it reaches the bottom of the slope it is going at its fastest speed.

We could measure the energy by seeing how long it takes to stop moving when it reaches the bottom of the slope. Try it. Make sure the test is fair. Fairness is very important in science investigations.

Alternatively you could involve it in a collision at the bottom of the slope…..say some cardboard or paper and see how far the car can push the shape it collides with. That would be another way to measure the ‘work’ that the moving car could do.

Damian, think about it. Experiment, and let me know how you got on.

Science Master

“Is time travel possible ?” asks Lachie (9)

Thanks for the question Lachie . My friend is correct, Albert Einstein thought that time travel would be possible because of something he called relativity. It seems to be about the time it takes to move through a given distance (space) and the speed of light. The faster you go the slower the time that has past. That is a very, very difficult idea to understand. Even I find it difficult ….. but lets try and give you an example

Suppose you could move through space at or around or about 186,000 miles per second, which is the speed at which light travels?

Say you were 9 years old when you left Earth in a spacecraft traveling at about the speed of light (which is much faster than we can achieve now), and celebrated only five birthdays during your space voyage. When you get home at the age of 14, you would find that all your classmates were 59 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

So, if your journey began today in 2018, it would have taken you only 5 years to travel to the year 2068, whereas it would have taken all of your friends 50 years. In a sense, this means you have been time traveling.

According to Einstein’s ideas you can only move forward in time you cannot move backwards. However we do not at the present time have any vehicle that could reach the speed of light so if you want to travel in time you might have to wait a little while.
(revised 23rd May 2018)

Liam (10) asks “Why does warm air go up?”

 

Thanks team. You are quite right we have to start at the beginning to really understand why warm air goes up. Let’s start by looking at what is air?

Air is a mixture of small gas particles (called molecules) of nitrogen, oxygen, carbon dioxide and some other gases. The image below could be a picture of what it would look like, if you could see it. What do you notice about it?

The red molecules are the oxygen, the blue the nitrogen and the others water and carbon dioxide. Imagine them moving around (I am trying to make an animation). Because they are moving they have energy.

If we heat the air, we are giving the molecules in it more energy. This makes them move faster and they move further apart.

The ‘thicker’ cold air surrounding the warm air drops into the space under the warm air and doing so pushes up the warm air which rises.

You can see this happening in a beaker of heated water.

Viper Astra (9) asks “What makes earthquakes happen?”

Viper, to answer your question it might be useful if we go back to the beginning. By the beginning I mean 4.6 billion years ago when the planet was first formed. Then it was a ball of molten lava. (1 billion is 1,000,000,000 or one thousand, million)

Over the next billion years the planet cooled and bits of crust formed on its surface. We call these bits of crust tectonic plates (the word ‘tectonic’ comes from the ancient Greek word for ‘building’ ……the crust is ‘building a surface’). These bits of crust got bigger, sometimes sunk into the molten sea they were floating on, but slowly covered the Earth.

Because they floated, the ‘plates’ of crust would have constantly experienced the movement of the molten ‘sea’ below them, so they moved and bumped into each other, and they are still doing that today. It is the movement and the, bumping into each other that causes earthquakes.

Watch this short video. It explains the different types of earthquake that can occur.

Thanks for the question Viper. Not sure about something then ask another question.

Hello (13) asks “How do tectonic plates work and influence earthquakes?”

Quite right my friend it’s all about convection. Warm water, air, oil, or any liquid/gas stuff  will move upwards (rise) when it is heated. Why. Think about it.

Lets think of an experiment (this is a science blog) where we can test this idea and then move on to the question that Hello asked.

The experiment

You will need a beaker of water, some pencil lead, 3  A batteries, two leads with attached crocodile clips and some food colouring and a dropper

Connect the pencil lead to the batteries using the leads. As the electricity passes through the pencil lead, the pencil lead will heat up. Drop the attached lead into the water. Look carefully at the water, what is happening. If you put a small screen behind the beaker of water and shine a torch on the water you will be able to get a better view of what is happening to the water.

OR

Drop a small amount of food colouring into the water.

Hopefully what you will see are convection currents that have been created by the water close to the lead  warming up and beginning to rise. The next question is WHY.

Warning. Do not use mains electricity. It could be very dangerous and kill you.

Why does the water rise?

When the water particles(molecules) come into close contact with the heated pencil lead they gain kinetic energy (see Science Master Special Energy), they move faster. The water molecules spread out so that in any given space there are less water molecules (less dense). This means that gravity comes into action and the colder water can begin to move into the space where the warm water was. The warmer water ‘floats’ on top of the cold water. The cold water then gets warm and and more cold water moves in and the original warm water floats up higher in the beaker. As the warm water rises it gets colder and more dense and eventually will join the column of cold water that is moving (by gravity) downwards toward the hot pencil lead. Wow…..I hope you can see the picture

The movement of the tectonic plates is caused by convection currents and it is this movement that can cause earthquakes. Hopefully when you watch the excellent video below you will see the links.

Hello. If you would like to question anything, please make a comment or ask another question.

 

 


(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Miwah (7) asked ” I hit a drum and it produced a banging sound. How did it do that?”

Miwah, what a great question. It really needs some thoughts from my team.

 

So Miwah what are your thoughts? What happens to the rice when the sound  occurs?

Is there anything around the rice? If there is will that behave in the same way?

Think, ask questions, see if there are links. That is what science is all about.

Any reader can ask another question or leave a Comment in the Leave a Reply box below

Science Master Special – Energy

Thanks team. I would like to add a few things.

Firstly the list of different types of energy is not complete. If you can think of some more then ‘Leave a reply’ in the box below.

Secondly it is interesting how the energy conversions can take place. For example a microphone converts sound energy into electrical energy and a loudspeaker does the reverse process, it converts electrical energy into sound energy. Can you think of other examples?

Any reader can leave a Comment in the Leave a Reply box below

Science Master Special – atoms, molecules, intra and inter molecular forces, heat energy and kinetic movement

There is a bit of everything in the title. Maybe the basis of everything as we know it up to now.

    • Atoms are the foundation of our understanding of matter (all the stuff around us).
    • Molecules are the the building blocks that are constructed from atoms to build the stuff around us.
    • The forces between atoms that make up the molecule are called intramolecular forces.
    • The forces between the molecules that the atoms make are are the intermolecular forces.
    • The study of molecular kinetics is the study of the movement of particles and the movement is usually associated with applied heat. Heat energy and movement are strongly linked. Heat something and it moves faster.

For a more detailed look at the structure of atoms look at this Science Master Special

Any questions?

If you have any please ask them in the Reply section below.

Isabelli (10) asked a follow up question on- Why are things absorbed and how does temperature affect water?

Isabelli, a couple of interrelated interesting questions. I asked my team to prepare the scene …be back later.

adsorption-absorption

First a little experiment. Put a small amount of water into a saucepan and place it on a heat source (parental permission required) carefully observe what happens (observation is an incredibly important science skill). Make notes of what you see. when the water is obviously boiling switch off the heat source and leave the water to cool down. Avoid moving it. Now repeat the experiment, again making notes on your observations. Are there any differences?

Look at the water molecules in the diagrams above. Water is a dipolar liquid. That means that there is an uneven charge distribution in each molecule. It has a negative ‘end’ and a positive ‘end’. This gives it the capability of making the Oxygen molecules (which are not normally dipolar) dipolar and subsequently creates an attractive force between the water and Oxygen molecule (bit like two magnets). The Oxygen molecules like this arrangement and are held within the water structure.

But …. if you heat up the water the water molecules begin to move about faster so the tentative attraction between the water molecule and the oxygen molecule breaks and it escapes from the water. Can this explain what you observed when you heated the water?

Thanks for your comment. Please feel free to ask further questions and make further comments.