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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 16106 letters have been answered. They are listed according to date.

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

List of most recent 15 letters





Resources helpful Education India
Person sending me noise Mental Health USA
Using roller skates in spaceship Gravity USA
Getting good grades Machines USA
Friction on Inclined Surface Friction Canada
Leyden jar Electricity Nigeria
Resolve components Physics Nigeria
Dark Matter SfC New Zealand
Reducing friction Physics USA
Pendulum and harmonic motion Motion Tanzania
Characteristics of the Moon Astronomy India
Speed of sound inside aircraft Sound USA
Calculating simple pendulum Physics Motion Nigeria
Lazy eye History USA
Question Flash USA

Next 15 letters

Resources helpful


January 21, 2020


Your Education Resources page was super helpful for me when I was recently searching for some educational resources as, so I wanted to return the favour.

Also, I wanted to let you know that I have a site related to astronomy, where I published some content that might make a nice replacement.

Here’s the link:

I hope this helps and keep up the awesome work!

Prem - India (29329)


I am glad the material was useful to you.

I added a link to your site from


Best wishes for success in your work.

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Person sending me noise

Mental Health

January 14, 2020


A person is putting a noise around me all the time, in my car. In my apt. And especially after I have eaten. The purpose is to put me to sleep or make me unconscious. I need to record these sounds for proof or evidence that this is happening to me. what to do ?

Learline - USA (29319)


Do you have any idea who this person is that is sending you these sounds? Why would the person do this?

Also, it is possible that they are internal sounds caused by problems in your inner ear, similar to Tinnitus.

A good place to start is be getting a checkup from your doctor. Also, try to identify the person.

Best wishes in solving this problem.

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Using roller skates in spaceship


January 13, 2020


if the astronaut had roller skates on and was felling the effects of artificial gravity since the wheels are in contact with the outer shell, whould he stay in one place since the wheens would be turning?

art - USA (29317)


That is a good question.

If the roller skates had magnetic wheels, such that they would keep the astronaut in contact with a steel outer shell floor, he could skate around the outer shell.

If he went in the direction of rotation, it would slightly increase the feeling of gravity, while moving in the opposite direction would decrease that feeling. However, the effect would be negligible since his velocity would be small.

I updated the Artificial Gravity in Spacecraft page to reflect information about using skates.

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Getting good grades


January 9, 2020


is to get GOOD GRADES

juan - USA (29315)


See: Getting Good Grades for more information.

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Friction on Inclined Surface


January 8, 2020


So, what you are saying is that the coefficient of static friction on an inclined surface is greater than on a flat surface?

Urooba - Canada (29313)


Sorry for the confusion.

The coefficient of static friction on an inclined surface equals that on a flat surface.

I've updated Static Sliding Friction on an Incline to clarify the issue.

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Leyden jar


January 8, 2020


What is the meaning of foil, and how can i find leyden jar

Andara - Nigeria (29314)


A Leyden Jar is simply a glass container that has aluminum foil on the inside and outside. It is also a form of capacitor.

See: Storage of Electrical Power for more information.

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Resolve components


January 2, 2020


How can I get your materials, how can I know how to resolve component, the understanding

Okesanjo - Nigeria (29306)


What are you trying to do concerning this subject?

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Dark Matter


December 28, 2019


Hi Ron - hope you got my previous message - would really love to hear from you in regard to things you have written about dark matter and Bohr model. Just want you to know I am genuine - not a crackpot - although my wife would tell you differently ! I have a Phd but have been in and out of science a bit like yourself and am now a school teacher . Im in New Zealand, have published papers (Biology/genetics) - a long time ago. I have a burning issue to discuss about dark matter which we seem to be on the same page about.
Look forward to hearing from you - Dave Nicol

David - New Zealand (29303)


I'm in the process of updating material I have on Dark Matter. I'll let you know when I get things ready. Feel free to ask some questions. They could help with important issues.

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Reducing friction


December 20, 2019


I'm doing a project to how to reduce friction, so how do you reduce friction?

sameera - USA (29300)


See Reducing Sliding Friction.

Also see Friction Experiments.

Best wishes for success in your project.

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Pendulum and harmonic motion


December 17, 2019


Why simple pendulum is not simple harmonic motion

Moh'd - Tanzania (29297)


If the pendulum is let free at a small angle, its motion can be considered simple harmonic motion.

I added a sentence to state that fact in Equations for a Simple Pendulum.

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Characteristics of the Moon


December 15, 2019


Phisical characteristics on the Moon

Sarat - India (29294)


Characteristics of the Moon include its distance from the Earth (384,400 km), diameter (3479 km), mass (7.35*10^22 kg), density (3340 kg/m^3), and temperature (107°C during the day and ?153°C at night).

See Characteristics of our Moon for more information.

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Speed of sound inside aircraft


November 21, 2019


Disabled veteran with PTSD, my brain turned on at 5 a.m. today with the idiot question of what is the speed of sound inside an aircraft flying faster than sound. Wide awake now, I assume that the speed is relative to the enclosing vessel, and that the speed of the aircraft is essentially irrelevant. Except possibly at lightspeed ...

Karen - USA (29274)


That is a good question, and you are correct that the speed of sound inside an enclosed aircraft is independent of the aircraft's external speed.

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Calculating simple pendulum


November 20, 2019


what is the method of calculating simple pendulum

MAUAN - Nigeria (29272)


You can measure the frequency that a pendulum swings with a stopwatch.

To calculate the frequency, you must measure the length of the rod or wire and use the equation: f = [SQRT(g/L)]/2PI.

(See Equations for a Simple Pendulum.

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Lazy eye


November 14, 2019


Did you also know both Lincoln and Kennedy had a lazy eye? Just look at the pictures.

Linda - USA (29263)


Thanks for the interesting information.

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November 7, 2019


Learning builder options/settings. Recapture administrative role.

Jason - USA (29258)


I'm not sure what you are trying to do.

Unfortunately, Adobe Flash is not supported in many browsers. Thus, alternative applications are being used to create animations.

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Next 15 letters


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