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Feedback Blog by Ron Kurtus. Key words: answers to reader's questions, information, assistance, School for Champions. Copyright © Restrictions
Feedback Blog
Each day readers send in questions and feedback concerning the various lessons in the School for Champions website. A total of 14090 letters have been answered.
List of most recent 10 letters
Title |
Subject |
Country |
| Why are Alkynes non-polar molecules? | Chemistry | South Africa |
| Is ultrasound be harmful to the human ear? | Physics | India |
| Changing AC to DC electricity | Physics | India |
| Sound detectors | Physics | Nigeria |
| Needs derivation for rolling friction | Physics | Singapore |
| Wants to become an Economics professor | Education | Ghana |
| Are chloroform and ethanol polar or non-polar? | Chemistry | Bangladesh |
| Writing a book on character | Grades | Nigeria |
| I get sick when having to speak to groups | Speaking | Uganda |
| Who discovered the atom? | Physics | South Africa |
Chemistry
Why are Alkynes non-polar molecules?
May 21, 2013
Question
Why the Alkyne are non-polar molecules
seipati - South Africa (23704)
Answer
Alkynes are non-polar because they cannot be dissolved in water, as do polar molecules. However, alkynes but do dissolve in other non-polar substances. A rule is that like substances dissolve in like substances.
Physics
Is ultrasound be harmful to the human ear?
May 19, 2013
Question
Will ultrasound be harmful to human ear?
Nandini - India (23700)
Answer
I could be harmful if the volume or amplitude is high enough. Ultrasound provides more energy than normal sound frequencies, but its amplitude is usually not that high.
Physics
Changing AC to DC electricity
May 18, 2013
Question
Pls, tell me that,does a transformer can covert AC to DC?
If yes then how? pls rpl me.I need to know as soon as be possible.
Rahul - India (23696)
Answer
A transformer only changes the voltage of AC electricity. A device called a rectifier changes AC to DC on large scale. The are also called adapters when you convert AC to DC for small devices.
Physics
Sound detectors
May 18, 2013
Question
Natural sound detector and man made sound detector
Christian - Nigeria (23697)
Answer
Your ear is a natural sound detector. A microphone is a man made sound detector.
Physics
Needs derivation for rolling friction
May 18, 2013
Question
Hello,
I am a high school student and I am writing a research paper in IB and I need to figure out the frictional force acting on a rolling bar of copper on two rails of aluminium. To do this, I need to figure out the coefficient of rolling friction. I understand that the equation to figure out the coefficient is on the web page but, my teacher asked me to find a derivation of the formula. I have searched many books and websites but I cannot seem to find it anywhere. If it is not to much to ask, would it be possible for you to show me how the equation: ﾼR = v/(tg) is derived?
Thank you
Alto - Singapore (23699)
Answer
The equations for rolling friction seem to be empirical or from experiments. I've never seen a derivation of the equations.
One resource that might help you is Rolling friction and rolling resistance.
Rolling Resistance also gives some information that may apply.
I hope this helps in your paper. Best wishes for success.
Education
Wants to become an Economics professor
May 17, 2013
Question
I am a young Ghanaian aged 22 years. I had always dreamt of becoming a professor emeritus in Economics. After completion from the Senior High School, I was forced to pursue a diploma in Nursing because of financial difficulties. I have completed the nursing but, because of the divertion, I fell I have deviated from my ambitions. I am prepared to do what it takes to get me back on track but look stranded. I therefore need an advice from you as to how to go about it because, I don't the money to change the course but don't also want the nursing.
Simon Kwesi - Ghana (23695)
Answer
It is good that you have worthy goals. Sometimes a person must take a round-about route to achieve their dreams.
Nursing is a profession that is in demand, so you should be able to get a job in the field. This will give you the opportunity to save money that will allow you to pursue your Economics degree, even if on a part time basis at first.
While working in nursing, it might be worthwhile to learn about the financial aspects of the medical industry, as well as the economic impact to society. This will help you in your studies, as well as your job.
Of course, you should always do your best in your present job, even if it is not your first choice. But still, don't give up on pursuing your dream. Your achievement will taste that much better when you toward it indirectly.
Best wishes on your success. I know you will gain the position you desire.
Chemistry
Are chloroform and ethanol polar or non-polar?
May 16, 2013
Question
chloroform and ethanol are a polar or non polar compound?if it is.then please answer me some details.
shefali - Bangladesh (23692)
Answer
Polar molecules are water soluble, while non-polar molecules are fat soluble.
Chloroform is more soluble in fats than in water, thus it is classified as non-polar.
Ethanol is polar, since its oxygen molecule draws electrons towards it due to its high electronegativity, causing a negative charge around itself.
Grades
Writing a book on character
May 16, 2013
Question
Thank much for dis opportunity. Am writen a book on human character. So please is dere any contribution dat u can render or any sugestion to make my book looks matured? Thanks!!
Wilfred - Nigeria (23694)
Answer
Human character is a fascinating subject. Look at my section on Character to get some ideas on the subject.
In writing a book, it is important to define who your intended audience is. You should also write a short description of your book to help define your purpose. A synopsis is important to define the book in your mind, as well as to sell the idea to publishers.
Best wishes for success in your new book.
Speaking
I get sick when having to speak to groups
May 14, 2013
Question
hi am called Juliana a student i relaiesd that my public speaking potential are bad no matter what kind of courage i get from peers when i cames to that matter i even get sick what can i do? cos i need that subject in my career
Juliana - Uganda (23686)
Answer
It is true that being able to speak in public can be valuable in your career. Thus, it is important to practice speaking to become comfortable with doing it.
The goal in speaking is to communicate information to the other people. Often speakers get nervous when they don't have a clear idea about what to say or are trying to impress others.
You don't worry about impressing your friends or worry about making a mistake, do you? The same attitude can be taken when speaking to a group. Think in terms of making sure they understand what you want to say. This will reduce your anxiety.
Also, check local schools if there are courses or organizations on public speaking. They are good places to practice your speaking.
You are on the right track, and I am sure you can overcome your fears.
Best wishes in your public speaking.
Physics
Who discovered the atom?
May 13, 2013
Question
who is the first person to discover an atom and what did he/she use?
karabo - South Africa (23683)
Answer
Ancient Greek philosophers Democritus and Leucippus proposed that matter was made up of tiny particles they called atoms. In the 19th century, scientists John Dalton and Amedeo Avogadro were able to prove the existence of the atom.
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