Each day readers send in questions and feedback concerning the various lessons in the School for Champions website. A total of 15769 letters have been answered. They are listed according to date.
You can read them to further your understanding of the subjects.
|Lecturing about Physics||Motion||Somalia|
|Why is the KE at infinity zero?||Gravitation||USA|
|Total energy of falling object||Gravity||Nigeria|
|Thanks for the resources||Experiments||USA|
|Submerging object in a fluid||Fluids||Uganda|
|Artis Gilmore should be included in list||Sports||USA|
|Speed and gravity||Gravity||India|
|Woman flies off a motorcycle||Force||USA|
|Suggested resource||Mental Health||UK|
|Molecules of solids are closely packed||Matter||Bangladesh|
|Microwaves and polar molecules||Chemistry||India|
|Very good content||Thanks||Force||India|
April 18, 2017
I'm going to be graduating from college at the end of this spring semester and have been trying to educate myself on financial literacy. I just wanted to say that I found your personal finance resources to be better than those of my college. The only topic that I would like to offer a suggestion about is the lack of personal finance resources that are specifically targeted to new college graduates. Since April is financial literacy month and also close to the end of the school year, it's the perfect time to provide new resources for college graduates. I’ve been doing a lot of research on this topic and have kept my favorite financial literacy resources saved in a bookmarks folder. I was thinking other students or recent graduates on your page may find them helpful as well, so I wanted to see if you'd like to check them out.
Carl - USA (28010)
Yes, I'd be interested in seeing your suggested resources to add to the site.
Lecturing about Physics
April 17, 2017
Dear Sir, I thank you for your effort on this subject, this subject (physics)I like so much and I'm a lecturer of this subject. can you help me plz to send me more topics I like to know something more about it?
BAKAR - Somalia (28003)
The Physics index shows an extensive list of subjects covered in the website. They should help out with needed information.
If there are other subjects you want to know about, let me know.
Best wishes for success in your lectures.
Why is the KE at infinity zero?
April 15, 2017
I can see why the PE is zero at infinity since the R is infinite. Why is the KE at infinity zero?
Ray - USA (28002)
The theory is that at infinity, the total energy (TE) of the object is zero. Since the potential energy (PE) is zero, the velocity of the object also slows down to zero, such that its kinetic energy (KE) is zero.
However, this whole concept is highly hypothetical. One assumption is that the Universe extends to infinity. That may not be the case. The size is estimated at 156 billion light years across. (See Characteristics of the Universe).
Another problem is that the equations do not take into consideration the effect of other suns and galaxies.
But the equations are a good approximation.
Total energy of falling object
April 14, 2017
a ball of mass 8kg falls from rest from a height of 100m, neglecting air resistance, calculate its total energy after falling a distance of 40m.
damilola - Nigeria (28001)
The total energy is PE + KE.
After falling 40m, the object is 60m from the ground and has a potential energy PE = mgh = 8 * 9.8 * 60 = 4704 joules.
See Gravity Velocity Equations for Falling Objects to get the velocity of the object. v = SQRT(2gy). Thus, the kinetic energy of the object is KE = mv^2/2 = 2mgy = 2 * 8 * 9.8 * 40 = 6272 joules. Thus, the total energy should be PE + KE = 10976 j.
Thanks for the resources
April 13, 2017
My daughter Ava and I just wanted to reach out and say thank you for your Experiments Resources page. Ava has expressed a real interest in (and knack for) science the past couple of years. This year she decided to join the school's science club - a HUGE step for her. She's generally very introverted and shy. My husband and I haven't been successful in getting her to join anything until now.
Since joining the club she's been constantly on the hunt for new science websites and experiments to try. She came across your page and it has been so great for her I wanted to reach out and say thank you. I can't tell you how happy I am that she's found a hobby she loves so much - especially an educational one!
When I told Ava I was going to email you to thank you for your page, she suggested (insisted) I tell you about this other page she loves on "Car Science Experiments." She thought it might be a good addition to your page. I know the science club used one of the experiment ideas on there for rubber band cars or something of that nature - so hopefully you find some use for it too.
Thanks again and enjoy the rest of your week!
Susan - USA (27999)
I'm glad that the material has been useful to Ava. It is great that she has found an interest and knack in science and experiments. Her love of science can go beyond a hobby into a great career. And I am sure she will be successful in the things she does.
I added the link for the Car Science Experiments on the Experiments Resources page and included a "thank you" to Ava.
I am sure you are proud of your daughter. Best wishes to her success.
Submerging object in a fluid
April 7, 2017
Explain what is observed when an object of density to that of the fluid is submerged in it.
Ibra - Uganda (27990)
If an object has the same density of the fluid in which it is submerged, the object will remain submerged. However, the depth of the fluid or liquid will increase according to the volume of the object.
Artis Gilmore should be included in list
April 6, 2017
The fact that Artis Gilmore is not included in the 50 best NBA players is a crime. Ask Kareem about Artis, as I did. Ask others who played against him. Ask Hubie Brown who coached him.
Kareem said he hated when Artis came to town. "He was the only guy who could defend me, honestly. And he was the strongest man I ever played against, period."
Glenn - USA (27987)
Thanks for the suggestion. I added mention of Gilmore. But actually, since that list was made up in 1996, it really should be updated to include modern players. Perhaps even listing the top 100 players would be appropriate.
I plan to update the whole list soon
April 5, 2017
I am Alex Nordeen Editor at Guru99. Our Goal is to provide Fun and Free Education for ALL
I was doing some research on SQL and I came across your page
I want to highlight that we recently created tutorials on SQL that took 190+ hours to create with beautifully annotated screenshot, and is very comprehensive.
This tutorial is created by a Google veteran and I have personally edited them. The course covers SQL Basics like Database Fundamentals, Design,
· It also Covers SQL Basics Commands, Data Sorting, Regular Expressions & Wild Cards.
· We also touch on advanced topics like SQL Functions used in PHP, Null value, Keyword, Sub-Queries in MySQL, and Creating an Application using MYSQL
Do you feel it could be a good fit for your audience? Might be worth a mention :)
Here is the Link: http://www.guru99.com/sql.html
I'd love to know what you think!
Alex - USA (27986)
Thanks for the resource. I added it to the SQL Resources page.
Best wishes for success in your tutorials.
Speed and gravity
April 3, 2017
1. How the speed is the factor to reach our future not speed of light any speed?
2. Why the time of our Earth is different from space-time and how much difference?
3. Why the light is not escape in Black hole with figure and example?
4. What is space-time curvature?
5. What is difference between acceleration and acceleration due to gravity?
Amit - India (27983)
According to the Theory of Relativity, time slows down with speed, especially when an object is traveling near the speed of light. However, going into the future does not seem possible. Since the Earth is not traveling at a great speed, its time is similar to space-time.
A Black Hole has such great gravitational forces that even light cannot escape. That is why it is called "black".
Acceleration is the rate of increase of velocity. That can be caused by some force, including the force of gravity.
April 2, 2017
I am a writer of science topics and have a website www.science4fun.info/ which is about teaching the kids about science with interesting articles and easy-to-do experiments. its motive is to provide science education free of cost and free of ads to enhance the interest. I want to deliver my website to every science student. I will thankful to you, if you can check the website's physics section at http://science4fun.info/physics and include in your physics resource page under the name "Physics for Kids" for the students.
I look forward to hear from you soon. Thank you
Abdul Wahab - India (27980)
I added a link to Fun Science for Kids at Physics Resources. Best wishes for success with your website.
Woman flies off a motorcycle
April 2, 2017
To whomever can help me I have serious question. I'll get right to it. If a motorcycle was going an unknown mph and hit a object that cause it to immediately cause it to stop. And threw a 140 pound woman 100 feet. How would I calculate the mph. What would I need information wise? I really need guidance in how to figure this out very soon.
Felix - USA (27981)
The kinetic energy of the woman on the motorcycle is KE = mv^2, where m is the mass (not weight) of the woman and v is the velocity. If she is thrown 100 feet, there was some air resistance but also the fact that she fell from the motorcycle to the ground. How high was she up on the bike?
See Effect of Gravity on Sideways Motion for some equations on how far she would go from a given height.
April 1, 2017
while browsing through the addication Resource website, I found the resources section to the both helpful and easy to navigate. As an editor for AlcoholAareness.org,
a drug and addiction information resource, l've seen the benefits to spreading awareness about alcohol abuse and i am glad your website connects readers to this information.
The reason I'm contacting you today is to ask if you can add our site as a link.
Sasha - UK (27978)
That you for the suggested resource. I added a link at Mental Health Resources - Alcoholism.
Molecules of solids are closely packed
March 31, 2017
Why the molecules of solids are closely packed together?
Samin - Bangladesh (27974)
Because the temperature and kinetic energy of the molecules is lower in solids, they tend to get packed closer together. As the temperature goes up, the molecules move faster and get further apart. See for more information.
Microwaves and polar molecules
March 31, 2017
Why polar molecule are microwave active
saurabh - India (27975)
Microwave ovens work by causing polar molecules to spin rapidly and thus heat up the material. The wavelength of the microwave is such that its frequency or change in direction works well in causing the polar molecules to rotate. Non-polar molecules are not really affected by the microwave radiation.
Very good content
March 31, 2017
very good content
Anjali - India (27976)
Thank you for the kind words. I am glad the material was useful to you. Best wishes for success in your studies.
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