List of Topics

SfC Home > About the SfC >

 

Feedback Blog

Each day readers send in questions and feedback concerning the various lessons in the School for Champions website. A total of 15795 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

Viewpoint on gravitation and Big Bang theory Physics Gravitation Bangladesh
 
Helped me understand a difficult problem Thanks Physics USA
 
When is separation zero distance? Gravitation India
 
Is sound bent toward the ground? Sound UK
 
Confusion about calculations Motion USA
 
Solenoid and electromagnet Magnetism India
 
Give examples of using force Physics Force Malaysia
 
Alzheimer's resource Aging USA
 
Using adapter between plugs Physics Electricity New Zealand
 
Why is there a gap in a sound wave? Waves India
 
Can noise cancellation stop tinnitus? Sound UK
 
Can a person mess with your 6th sense? Senses USA
 
Why does an apple change color when cut open? Chemistry India
 
Voltage for vacuum pump Electricity New Zealand
 
Seeking permission to use image Magnetism Singapore
 

Next 15 letters

 





Viewpoint on gravitation and Big Bang theory

Physics

June 19, 2017

Question

Near about 14 billion years ago Allah/God the big bang and started evolution, now 7 divisible gravitation worlds.

“Gravitational worlds, they are moving or changing the orbit with their all family members depending on the nuclear of each other”. In this way- There has been incidence of full view of the universe at the very exact copy/invitation of the visible diagram solar system in the gravitation world. The universe has seven divisible, the first one of which is unit and the rest six are collective. The collective six gravitation are three invisible and the rest three are visible. The visible gravitation worlds are stars, planets and minor planets. The invisible gravitation worlds are black holes of various energy levels, the first one of which is the primordial black hole or Allah/God of the nuclear fusion of the universe. There have been collective six gravitation divisible of the big bang in future from the big black hole or Allah/God. At the first phase or level of the divisible is the black hole of the nuclear fusion of the clusters of galaxies or black hole named quasar. The second phase gravitation world of the quasars in future are of the black hole named pulsar or nuclear fusion of the cluster of galaxies. The third gravitation world of the pulsars in future is of the last black holes or nucleus of galaxy or the nuclear fusion of the constellations.

New Discovery of the Universe: https://shahidurrahmansikder.wordpress.com/tag/god/

Pope: The most important news- about the God, Big Bang & Evolution at https://plus.google.com/104669722445739033329/posts/MQ9wQejCRLQ

Shahidur Rahman - Bangladesh (28099)

Answer

Thanks for the information and interesting viewpoint on gravitation.

Return to List

Helped me understand a difficult problem

Thanks

June 18, 2017

Question

Thank you very much for this webpage. It helped me understand a difficult problem on my physics homework. I really appreciate you taking the time to make such a detailed and clear page.

Cheyenne - USA (28098)

Answer

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

Return to List

When is separation zero distance?

Gravitation

June 17, 2017

Question

1. Husband 70kg and wife 80kg are standing 1 mtr app art. At what they will come to zero distance by Gaby universilnal gravitational law ?

Prasad - India (28095)

Answer

The force is measured from the centers of mass of the two objects or people. Even when the husband and wife come into contact, there still is a separation between their centers, such they never will be at zero distance. See Gravitational Attraction Between Boy and Girl for more information.

Return to List

Is sound bent toward the ground?

Sound

June 15, 2017

Question

A simple question that I assume has a simple answer. I have assumed that noise travels in all directions from the source of the noise. Does it go in a straight line assuming no distortion by wind? So if noise from a road is reflected and absorbed by a sound barrier the direct undiluted transmission noise will be reduced. Assuming the above is correct, my question is will noise passing over a noise barrier just exhaust itself and not return to land or will it be forced down to the ground and house level by any force other than wind? What type of distance will be involved and will the situation be exactly the same with or without a sound barrier added close to the source of the road noise, please? Many thanks.

ROBERT - UK (28094)

Answer

Some of the noise from a road that passes over a wall or noise barrier can be redirected toward the ground due to diffraction of the sound at the edge of the barrier. See Diffraction Affects Blocking Noise.

The amount of the diffraction or bending is a function of the frequency of the sound. I'm sorry, but I don't have the calculations for determining the distances or bending of the waves.

Return to List

Confusion about calculations

Motion

June 13, 2017

Question

I follow you calculations up until the last part when you multiply the 6.28 * Square root of (0.2). I suspect it has something to do with the /sec/sec. could you explain a little further? Thanks for you time in this matter.

Jim - USA (28090)

Answer

The calculations go: 2 * 3.14 * ?(2/9.8) = 6.28 * ?(0.2) = 6.28 * 0.45 = 2.8 sec.

Since 2/9.8 = 0.204, I rounded it off to be 0.2. Since this caused some confusion, I updated the page to show 0.204 and changed 0.45 to 0.4517. The answer is 2.837 or rounded off to 2.8 sec.

Return to List

Solenoid and electromagnet

Magnetism

June 13, 2017

Question

Why solenoid is used for making electromagnet

Nishant - India (28091)

Answer

A solenoid is an electromagnet without the iron core in it. The solenoid can be used to pull a core inside it.

Return to List

Give examples of using force

Physics

June 12, 2017

Question

Name one examples when force can stop motion.

Name one examples when force can change the shape and size of an object

Nicholas - Malaysia (28088)

Answer

You can push on a rolling cart to stop its motion.

You can compress a foam rubber ball to change its size and shape.

Return to List

Alzheimer's resource

Aging

June 12, 2017

Question

My grandmother on my mom's side suffered from dementia in her last few years.

It was extremely hard on my mom, who was the one sibling who lived near enough to take care of her. There were days when she was so sweet and thankful to my mom for loving her and being there for her. Then there were those days when grandma seemed to absolutely hate my mom and not know who she was. Yet my mom was still loving and dedicated, caring for her until she passed.

With that on my mind, I was looking for helpful resources to include in an upcoming roundup on caring for and understanding loved ones with Alzheimer's and other forms of dementia, when I found your resources page. Thank you for your effort in keeping those resources up to date.

Just thought I’d share this in-depth guide to improving safety for loved ones with Alzheimer's or Dementia who are living at home like my grandma did, so you can include it in your page.
How to Make a Home Safe for a Loved One with Alzheimer’s or Dementia
https://www.homesecuritylist.com/alzheimers-dementia-home-safety/

Either way, thank you for your effort in keeping those resources up to date, and for supporting my goal of helping to make home a safer place for our loved ones who suffer from Alzheimer's or dementia.

Yvonne

https://healthhired.co/

Yvonne - USA (28089)

Answer

Thanks for the suggested resource. I added it to Healthy Aging Resources.

Best wishes in your efforts to make home safer for loved ones with Alzheimer's.

Return to List

Using adapter between plugs

Physics

June 11, 2017

Question

can I use an appliance from south Korea - 220v in New Zealand 230v ? from your chart it would also appear that the frequency will be different also will this cause problems? thirdly the plug types are different is it ok for an electrician to change the plug from c to l

Tina - New Zealand (28086)

Answer

The voltage difference should not affect things. However, a 60Hz appliance might perform slower with 50Hz. If there are timers or clocks involved, it might make a difference. It is good to check with the manufacturer website to see if things would work sufficiently.

An adapter plug could be used if the prongs are different. An electrician should be able to make the proper connections.

Best wishes for successful use of your appliance.

Return to List

Why is there a gap in a sound wave?

Waves

June 10, 2017

Question

Why there is an gap between successive compressions and successive rarefactions?

Abhisheka - India (28082)

Answer

There is no real gap between compression and rarefaction in sound waves. The wave shape is a continuous sine wave. That means one half of the waveform is compression, followed by an instantaneous change to then become a rarefaction.

Return to List

Can noise cancellation stop tinnitus?

Sound

June 10, 2017

Question

I have tinitus but am luky as my mind can cancel it out, BUT many people cannot and it drives them mad
can this technology be used for this

len - UK (28083)

Answer

It would be nice if noise cancellation would help out, but unfortunately it only cancels external noises. Tinnitus is the perceptions of sounds in your inner ear. There are some medications that can help. See Tinnitus

Return to List

Can a person mess with your 6th sense?

Senses

June 10, 2017

Question

Can A person mess with your six Sense if so how would you act

Michael - USA (28084)

Answer

Our definition of the sixth sense is precognition or being able to sense future events. It is different than being able to read or affect minds.

It is difficult or even impossible for others to mess with your senses, except by some trickery. You can usually tell if you are being tricked.

Return to List

Why does an apple change color when cut open?

Chemistry

June 9, 2017

Question

Why apple turns into red colour after cutting into slides?

Maddakam - India (28081)

Answer

Apples start to oxidize once they are cut open. That is the reason the colour changes.

Return to List

Voltage for vacuum pump

Electricity

June 7, 2017

Question

hi, i'm looking to buy a vacuum pump from china rated 220v-50hz.can i use it in new zealand which is 240v-50hz with no problems?it has the same plug connection as nz.
regards
dave

dave - New Zealand (28078)

Answer

AC voltages vary by about 10% from the listed value. So using a 220V pump at 240 volts should work fine.

Best wishes with your new pump.

Return to List

Seeking permission to use image

Magnetism

June 6, 2017

Question

To Whom It May Concern,

I am Christine from the Copyright team of Kydon Learning Systems Institute. My team consists of myself as the Learning Designer and Project Manager, Bing Ying.

We are writing on behalf of Dr So Ping Lam from the School of Electrical and Electronic Engineering, in Nanyang Technological University, Singapore, who teaches EE3010, Electrical Devices and Machines.

As the appointed Content Partner, we are responsible for converting the course EE3010, into a blended learning course which video lectures will be produced and uploaded into NTU’s learning portal. The image on "right-hand rule for electric wire" which we are seeking copyright clearance will be used in the video lectures and students’ lesson materials. Proper citation using APA style will be used for each image to acknowledge your work. The blended course will be launched in January 2018. There will be about 150 undergraduate students who will have access to the learning portal to participate in this course.

We are flexible about restrictions regarding modification and use, so feel free to let us know about it.

Alternatively, if we do not receive your reply, we will add the citation (to mention that the source taken from your website) in our work.

We look forward to your favourable response in granting us the permission to use the image.

Thank you and hope to hear from you soon.

Yours sincerely,

Christine - Singapore (28076)

Answer

You have permission to use the "right-hand rule for electric wire" image in your blended course with no copyright or modification restrictions, as long as it includes the proper citation.

Our website is intended for the advancement of learning and education.

Best wishes for success in your blended learning project.

Return to List

Next 15 letters


Misc


Questions and comments

Do you have any questions, comments, or opinions on this subject? If so, send an email with your feedback. I will try to get back to you as soon as possible.


Share

Click on a button to bookmark or share this page through Twitter, Facebook, email, or other services:

 

Students and researchers

The Web address of this page is:
www.school-for-champions.com/sfc/
feedback_blog.cfm

Please include it as a link on your website or as a reference in your report, document, or thesis.

Copyright © Restrictions


Where are you now?

School for Champions

Feedback Blog




About the SfC


Subjects in website



Let's make the world a better place

Be the best that you can be.

Use your knowledge and skills to help others succeed.

Don't be wasteful; protect our environment.

You CAN influence the world.





Live Your Life as a Champion:

Take care of your health

Seek knowledge and gain skills

Do excellent work

Be valuable to others

Have utmost character

Be a Champion!



The School for Champions helps you become the type of person who can be called a Champion.