Feedback Blog
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 most recent 15 letters
Title |
Subject |
Section |
Country |
| Using hard wired chandelier with 240 VAC | Electricity | USA | |
| Comments on theory | Matter | India | |
| Theory comments | Matter | India | |
| Comparing the earth to an atom | Thanks | USA | |
| Moving the magnetic field | Physics | Electricity | USA |
| Where does Jesus stand in Unity? | Religion | USA | |
| When rocket thrust is reduced | Gravity | USA | |
| What is efficiency? | Machines | USA | |
| Relationship between Brownian motion and Kinetic theory | Physics | Matter | USA |
| Branches of Physics | Physics | Kenya | |
| Suggested resource | Security | USA | |
| Velocity equations | Physics | Gravity | India |
| Applying a force | Force | Philippines | |
| Vectors in friction | Friction | USA | |
| Confusion about inertia | Force | India | |
Using hard wired chandelier with 240 VAC
Electricity
August 21, 2019
Question
I have a ‘hard wired’ chandelier that says 120V 60Hz AC Only. Can this be used in Kenya where it is 240V 50Hz AC? Does it being hard wired makes a difference?
Sam - USA (29156)
Answer
You could use a AC power converter to reduce the voltage to the chandelier, but it probably be more work than it is worth it, especially since the converter would have to be between the source and the chandelier.
The difference in frequency would not be an issue, but 240 VAC input would cause problems.
Comments on theory
Matter
August 19, 2019
Question
Actually you're theory is correct because all the things scientists found yet is just a theory.
All we have know till are based on hypothetical concepts. And it is true that human always contradict himself and creates a new theory.
Well if I say what if....
-Solar system = atom
-Electron orbits in elliptical orbit so as planets
-galaxy is just a big chain of atoms
-cosmic web are bonded big chain of atom
-and universe is just a molecule
What if things be like this.
So actually we can say that the deeper we look the bigger we see
Yug - India (29152)
Answer
Thanks for your comments and insight.
Best wishes in your studies.
Theory comments
Matter
August 19, 2019
Question
This theory of a solar system to be an atom can be true. Because we know that whatever scientists found yet are just theories based on hypothetical concepts and experiment. And it's is a fact that we makes theories and contradict ourselves and then again creates a new theory.
But what if it is true, what if
*Solar system be an atom
*Planets be electons revolving elliptically around sun (nucleus)
*Also sun has quiet very much mass and also creates a big depression on space time facbric.
*And galaxy are bonded atoms
*Cosmic web are chain of bonds of different atoms
*And finally universe and a molecule.
This thing clear one fact that as we look deeper we see things gets bigger.
And also as time is relative....
And we know that because of Heisenberg uncertainty principle that electron have a very movement or velocity.....but if we compare it to solar system it is very slow....
It maybe the cause of relatively of time.
And there are many more theories that can be true for proving that an atom is just solar system....
So as we go beyond universe we finds that there is another universe cause our as being one of those parallel universe.....!!!!!
And actually there is no end of anything we seen yet....!!!!
Yug - India (29155)
Answer
The theory and concept has many implications, as you observed. It can be an interesting study.
Comparing the earth to an atom
Thanks
August 16, 2019
Question
Just stumbled across this page tonight while googling "comparing the earth to an atom" ...etc. stuff that I've had on my mind for some time now (years!) And I just want to say, wow. I mean.. I'm just getting started, but, this is awesome.
Thank you for creating this website.
Desa - USA (29148)
Answer
Yes, it is quite an interesting analogy. I'm glad you enjoyed the material and found it useful.
Best wishes for success in your studies.
Moving the magnetic field
Physics
August 16, 2019
Question
I'm a tutor. Discussing electricity with students. This came up. If you move the field around the coil, instead of the coil moving, would that generate a current? Thank you!
james - USA (29151)
Answer
The first illustration in Generating Electrical Current shows a wire moving through a magnetic field. You could easily move the magnets and keep the wire stationary for the same effect.
Where does Jesus stand in Unity?
Religion
August 15, 2019
Question
I was born and raised as a Catholic but eventually became a non-denominational Christian. I believe in the bible and believe that Jesus is the Son of God. Where does Jesus stand in Unity?
peggy - USA (29147)
Answer
Unity Church followers believe that all humans are the children of God and share that divine potential. Thus, they believe in the divinity of Jesus, but only in the sense that Jesus is the great example of the Christ in physical form.
Thus, their view is not that Jesus came to save us from our sins but rather as an example of how to relate to God.
When rocket thrust is reduced
Gravity
July 20, 2019
Question
Could you also please address what happens if at 20m/s, the rocket thrust is reduced and maintained to exactly balance gravity?
Obviously we ignore other gravities, air resistance, etc.
It is my opinion that when thrust = gravity, velocity remains constant and all thrust energy is converted to potential energy.
Mike - USA (29117)
Answer
Once the rocket thrust is reduced to simply balance the force of gravity, the rocket will continue at 20 m/s (assuming no air resistance).
Since the potential energy of the rocket with respect to gravity is simply PE = mgh, where "h" is the altitude, PE will increase PE will increase at a constant rate and the thrust energy is converted into that PE.
What is efficiency?
Machines
July 12, 2019
Question
What is efficiency?
Aeesha - USA (29104)
Answer
The efficiency of a machine indicates how well its input energy is converted to useful output energy or work. In other words, efficiency is the output work divided by the input work.
Relationship between Brownian motion and Kinetic theory
Physics
July 9, 2019
Question
What is the relationship between Brownian motion and the Kinetic Theory of Matter?
Your content is rich on the topic.
Emmanuel - USA (29098)
Answer
The Kinetic Theory of Matter states that matter is composed of a large number of small particles—individual atoms or molecules—that are in constant motion.
On the other hand, Brownian motion is the erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium. Thus Brownian motion concerns the collisions of particles in motion due to the Kinetic Theory of Matter.
Branches of Physics
Physics
July 8, 2019
Question
What are the branches of Physics?
kevin - Kenya (29096)
Answer
Branches of Physics include:
- Classical physics
- Modern physics
- Nuclear physics
- Atomic physics
- Geophysics
- Biophysics
- Mechanics
- Acoustics
- Optics
- Thermodynamics
- Astrophysics
Suggested resource
Security
July 5, 2019
Question
Happy Friday!
My name is Felicia, and I volunteer in a Job Corps program for inner-city youth that has decided to enter our program to better themselves. They are doing this by learning a trade that will allow them to enter the workforce with a real skill set. I am writing on behalf of one of my students, Anthony, who is involved in our Network Cable Installation program. Anthony will be finishing the program soon, so he's been assigned a project to match resources with websites that future classes that include all of the jobs that kids in our program can pursue after they complete the program. While helping him with this project, we came across your website https://www.school-for-champions.com/SCIENCE/electricity_resources.htm. We want to say thank you for providing us with all your helpful information.
Anthony has already lined up a job with a well-known home security firm to install security systems in new residential construction and he is incredibly excited about it. In his research, he found this useful article about choosing a security camera system, and while the article alone is useful, what he really got excited about was the information on how to set up a security camera system after the install has actually been completed. Here is the article he found - https://www.cctvcameraworld.com/security-camera-systems.html
To graduate, he needs to show that he helped share information with others that could find his research useful. With this requirement in mind, would you please add a link to the article he found to your own website with all your other useful links? He's been having some trouble with the exercise and it has really been weighing on him. I'd like to surprise him with this and put his mind at ease that he'll be able to complete the program and take on the next chapter in his life. He has worked very hard at this and I am incredibly proud of him. Would you please add it for him?
Thank you again and thank you for your consideration.
Felicia - USA (29094)
Answer
Thanks for the resource. I added a link at Security Resources - Systems.
Best wishes for Anthony's success.
Velocity equations
Physics
June 17, 2019
Question
Would you please Explain the sign convention of g with the following examples
A)A ball thrown vertically upwards from the ground.
B)A ball thrown vertically upwards from a tower of hight h.
Find the maximum hight, find the time of flight and also velocity of ball before it reaches the ground.
S - India (29073)
Answer
The acceleration due to gravity (g) is positive toward the ground. When an object is thrown upwards, the force of gravity slows the velocity of the object.
See Gravity Equations for Objects Projected Upward..
To find the maximum height, you need the initial velocity upwards of the object, as well as the height from which it is thrown. The same is true for the time in flight.
Also see: Equations for Objects Projected Upward
Applying a force
Force
June 12, 2019
Question
When you apply the force, does it means there's a motion all the time ? And explain.
Norjanah - Philippines (29065)
Answer
When you apply a force on an object, that force must overcome any friction that prevents the object from moving. Once the force is greater than the resistance from friction or other resistance, the object will move.
If there is no friction holding the object back, it will move freely and accelerate according to F = ma.
Vectors in friction
Friction
June 10, 2019
Question
The frictional force can be represented as a vector in the direction of motion of an object on a surface. The normal force can be represented as a vector perpendicular to surface of the object. The usual equation is f = mu N. But when a vector N is multiplied by a number (mu) the result is another vector f of a different magnitude than the normal force but in the same direction. But the normal force is perpendicular to the frictional force. How is this possible? Please explain.
Robert - USA (29063)
Answer
The resistance due to friction is in the opposite direction of the motion of the object. Multiplying the normal vector N by a scalar number (mu) does not change the normal force. For example, if N was the weight of an object, changing the coefficient of friction (mu) would not change the weight.
Confusion about inertia
Force
June 3, 2019
Question
If a body of mass m is accelerated with acceleration 'a 'then force is na and inertia force also _ma ,so resultant force is zero then how body accelerated?
Abhishek - India (29060)
Answer
The concept can be confusing. The inertial force is simply what is felt and does not affect the resultant force.
I updated the Inertial Force page to help clarify the concept. I hope that helps.
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