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Each day readers send in questions and feedback concerning the various lessons in the School for Champions website. A total of 16082 letters have been answered. They are listed according to date.

You can read them to further your understanding of the subjects.

List of next 15 letters





Separation from time interval Sound USA
Details on starting a business Entrepreneurship Nigeria
Designing back cover Publishing India
Contact surface in rollers Machines Pakistan
Suggested resource Career Germany
Loudness of sound under water Sound Papua New Guinea
Dropping a piano Gravity USA
Direction of motion Machines Tanzania
Suggested resource Aging USA
Son is struggling with numbers in school Grades South Africa
Thanks for the voltage info Thanks Australia
Computer Science vs Chemical Engineering Career Uganda
What are quarks? Physics Sudan
Proof of value of constant Gravitation Nepal
Work to propel rocket upwards Gravity USA

Next 15 letters


First 15 letters

Separation from time interval


June 1, 2019


Two men stand a distance apart besides a long metal fence on a still day. One man places his ear against the fence while the other gives the fence a sharp knock with a hammer. Two sounds separated by a time interval of 0.5s are heard by the first man. If the velocity of sound in air is 330m/s and in the metal 5280m/s, How far apart are the men?

Moses - USA (29057)


You have to use some Algebra to solve the problem.

Let d equal the separation. Also d = v*t. The time for the sound to travel in each medium is t1 = d/v1 and t2 = d/v2.

If the time interval is (t1 - t2) = 0.5 s, then 0.5 = (d/v1 - d/v2) = d*(1/v1 - 1/v2), and d = 0.5*v1*v2/(v2 - v1)

Substituting v1 = 330 m/s and v2 = 5280 m/s in the equation will result in the separation.

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Details on starting a business


May 27, 2019


I need full details on how to start my own business.

Abdulrasheed - Nigeria (29052)


First of all, you need to define what sort of business you want to start. Do you want to sell a product or a service?

It is always good to start small before seeking investors in your business. Also, it is good to get others interested in your ideas.

Go through the lessons in

and also check many of the resource websites at:

Best wishes for success in starting and running your business.

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Designing back cover


May 21, 2019


Please suggest or design a book cover back cover or spine cover of a book based on the story:
A boy scores bad marks in class X and left his home.
After passing some years wandering here ad there he joins a assistant magician to a group.
He marries with the daughter of head magician
He wants His children should do further study and should not join as a magician.
The theme : Importance of Education

Dr Rajesh - India (29048)


First of all, you need a catchy title for your book that will get readers interested in it. Then on the back cover, under the title you need to have a few sentences that will summarize and create more interest. For example: "This book shows how a father wants to teach his children from the lessons learned from not having a good education."

You can then list highlight points from the book and perhaps comments from people who read your book.

Go to a bookstore or library and study the back covers of similar books.

Best wishes in writing, designing, and publishing your book.

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Contact surface in rollers


May 20, 2019


As the friction does not depend upon the surface of contact then how rolling reduces the friction?

Abdur - Pakistan (29046)


If you consider sliding an object across the ground, you can see that using rollers or wheels results in much less friction.

The only friction in using rollers is due to a slight "stickiness" an the contact surface. But this is negligible.

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Suggested resource


May 18, 2019


Hey School for Champions Editors,
I was doing some research on interview tips and noticed that you have this killer resource page on your site: . Awesome job!

Since you’re clearly an authority on the subject, I thought you’d be interested in checking out my article on "Best Interview Practices for Job Seekers". It’s super in-depth and I think it would make an awesome addition to your resource page (especially as your readers would love and benefit from it immensely).

Here’s the link if you’d like to check it out:

CEO Cleverism

Martin - Germany (29042)


Thanks for the suggested resource. I added a link at

Best wishes for success in your work.

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Loudness of sound under water


May 14, 2019


Is the loudness of sound greatest in water than it is in air

Willie - Papua New Guinea (29037)


The loudness or amplitude of a sound under water seems louder than in air. One reason is that in air, only your eardrum detects the sound. However, under water, your eardrum and your skull sense the sound. Also, sound travels faster under water.

You can test the loudness by comparing a sound from the clicking objects together above water and doing the same under water with your head also under water.

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Dropping a piano


May 12, 2019


Is there work done on a piano when you drop it from the fourth floor to the ground floor

eman - USA (29032)


Work is defined as the force required to overcome a resistance times the distance traveled.

Lifting a piano would require work to overcome the force of gravity or weight of the object. Work done by gravity in dropping a piano would be overcoming the slight air resistance.

Hopefully, no one is standing under the piano if dropped from the fourth floor.

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Direction of motion


May 9, 2019


With reference to the explanation given on the second class lever, you said the movement of both load and effort are in the same direction. THIS IS NOT CORRECT. Take an example of a wheelbarrow which in the second class, in it the load (weight) is directed downward while an effort which is applied is directed (acting) upwards, therefore the movements of these forces (load and effort) are opposite.
I'll be glad to get your reaction.

Issa - Tanzania (29029)


Thank you for your observations. With a wheelbarrow, you pull upward on the handles to raise the load.

I updated the images on Three Lever Classes to clarify the directions on the motions for the various lever classes.

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Suggested resource


May 8, 2019


Good Morning,

I hope your Wednesday is going well. My name is Garrett and I’m reaching out on behalf of Baylor University's Online Graduate Programs. I work with the university to distribute useful school-generated content to credible and relevant websites with similar content and audience interests.

Recently, I came across the "Healthy Aging Resources" page on the School for Champions website, located here:

I was impressed by the gerontology resources you've assembled and was wondering if you'd be open to sharing an additional resource with your community? 

If so, I’d like to suggest "How Communities Can Prepare for the Growing Aging Population," published by The MPH online program from Baylor University's Robbins College of Health and Human Sciences. This resource discusses how to make communities more inclusive for the older adult population. It offers examples from ten age-friendly U.S. communities and further examines how changes in things like transportation, housing, and outdoor spaces can help people age actively. I believe this would be an excellent resource for your community as it is relevant to the gerontology resources provided on the page.

Below is the URL to the resource:

Would you be open to sharing this resource with your community on the webpage?

Thank you for your consideration. Please feel free to contact me if you have any questions or need additional information. I look forward to hearing from you soon!

Best Regards,
Garrett Perry

Garrett - USA (29027)


Thanks for the suggested resource. I added a link at Healthy Aging Resources.

Best wishes for success in your work.

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Son is struggling with numbers in school


May 3, 2019


my son is doing grade 2 he is eighty years old he is olways strugling to pass at school am worried about it he is not good in counting numbers

Phelelani - South Africa (29024)


It is good that you are helping and giving him encouragement.

You might let him try out Counting Games for Kids on your computer. The practice can be fun for him and get him more interested in the subject. There are other similar websites to help young students practice.

I hope this helps. Best wishes for your son's success in school.

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Thanks for the voltage info


May 1, 2019


Thanks for the voltage info. Very helpful

Frank - Australia (29022)


I'm glad the material was helpful to you. Best wishes for success in your endeavors.

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Computer Science vs Chemical Engineering


April 30, 2019


which of the two can i study to be employed easily: 1.bachelors in computer science. 2.bachelors in chemical engineering.

atuhaire - Uganda (29019)


There is a demand for college graduates in both areas of study. The most important thing to consider is which are are you most skilled and that you enjoy the type of work.

Note that Computer Science is often used along with Chemical Engineering, so studying both would be good.

It is good to check with companies in your area to see what they have to offer. In this way, you can tell the potential and wages for the type of job you select.

For example, check out:

Computer Programming jobs:

and Chemical Engineering jobs:

I hope that helps. Best wishes for success in your career.

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What are quarks?


April 30, 2019


What are the quarks ,and did it found before or after the (the Big Bang Theory).

Abdelgadir - Sudan (29021)


A quark is a fundamental or elementary particle of matter that is part of such particles as protons and Neutrons. See Fundamental Particles of Matter.

Quarks were discovered around 1968.

The Big Bang Theory was proposed around 1929, although there were other similar theories many years before that.

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Proof of value of constant


April 24, 2019


Proof of the value of the gravitational constant is 6.67×10^-11

Aniket - Nepal (29010)


Besides the Cavendish Experiment, there have been many other experiments and astronomical measurements to establish the gravitational constant. However, there are slight variations in the values of the constant.

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Work to propel rocket upwards


April 14, 2019


My understanding of the force required to lift a rocket must be a force greater than gravity. No energy can be added without an applied force. Work requires a net force and adding energy is work and the energy of the rocket increases at the rate of climb. Thrust of mg can't add that energy. Power= Work/time is FV where force is F and V is the vertical climb rate and the power required is mg?h/?t or mgV. Could you explain how the rocket can climb without this work being done?

Clifford - USA (29001)


In order to lift or propel a rocket from the ground, the applied force or thrust of the rocket engine must overcome the resistances from gravity (weight) and inertia (acceleration). F = mg + ma.

Energy is not added to the rocket. (You need to be careful in defining your terms). The rocket's kinetic energy (KE) is a function of the mass of the rocket and its velocity: KE = (mv^2)/2.

The work done in lifting the rocket a given distance or displacement is: W = Fd. But also, the work done equals the change in kinetic energy. Since the kinetic energy is zero on the launching pad, the work done at some given point is KE = (mv^2)/2.

The rate of climb is simply the vertical velocity. The increase of the rate of climb is a function of the acceleration of the rocket.

The acceleration of the rocket is: a = F/m - g.

Also, the work done equals the change in KE.

I hope this helps to clarify the situation. It can be confusing.

Feel free to ask more about the subject.

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