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 15704 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

Title

Subject

Section

Country

5^6 times 8^6 Algebra USA
 
Need to update home voltages Physics Electricity USA
 
Can we use paypal in Myanmar? Finances Myanmar
 
Change frequency of LED light Physics Electricity USA
 
Pressure points in foot reflexology Health Philippines
 
Using CO2 for supercritical extraction Physics Matter USA
 
Gravitational force Physics Gravitation USA
 
Reducing aerodynamic drag Physics Friction Uganda
 
Correcting number of Jupiter's moons Astronomy USA
 
Motivations for good grades Grades USA
 
Superhero trying to outrun villan Physics Force UK
 
Wore a PIG pin History USA
 
Recommending mesothelioma resource Health USA
 
Weight of two containers of water Physics Fluids Egypt
 
Calculating speed of light for spectral line Physics Ireland
 

Next 15 letters

 




First 15 letters


5^6 times 8^6

Algebra

January 31, 2017

Question

hi, i have a question that is 5 to the 6th power times, 8 to the 6th power... how do i do this i asked everyone and they don't know how
thank you

noelle - USA (27847)

Answer

5^6 (5 to the 6th power) times 8^6 = 40^6 (40 to the 6th power).

(5^6)*(8^6) = (5*5*5*5*5*5)*(8*8*8*8*8*8) = 40*40*40*40*40*40 = 40^6

In general, (x^a)*(y^a) = (xy)^a

Return to List

Need to update home voltages

Physics

January 30, 2017

Question

On your page AC Wiring I encourage you to change all instances of "110" to "120" when referring to household voltage, since it is set (in the US) to 170 Vp, which ends up being approximately 120 VACrms.

Noji - USA (27841)

Answer

Thanks for pointing that out. Although 110 VAC is often used, the actual average between 110 and 120 is 117 VAC. But 120 is more commonly used. I changed the pages on AC from 110 VAC to 120 VAC.

I also updated the higher voltage from 220 to 240 VAC.

Return to List

Can we use paypal in Myanmar?

Finances

January 30, 2017

Question

Can we use paypal in myanmar

Ch - Myanmar (27843)

Answer

Apparently PayPal had been blocked on Myanmar, but it is now available. One site giving information is Payment from Myanmar with Visa. There are other sites also giving advice.

Check the PayPal site on service in Myanmar for some information.

Best wishes in using PayPal.

Return to List

Change frequency of LED light

Physics

January 29, 2017

Question

How can I change the frequency of an LED lifght?
Thank you

Chris - USA (27836)

Answer

Right now, LEDs come in only three colors: red, green, and blue. A combination of them is a white LED.

Each color has a specific electronic configuration. Unfortunately, engineers have not found a way to vary the output frequency of an LED.

Return to List

Pressure points in foot reflexology

Health

January 29, 2017

Question

1. what are the pressure points in foot reflexology?
2. what are their functions in each pressure points?

Jesus Ramon Neopolo - Philippines (27837)

Answer

I don't have the specific pressure points. You can check the various Resources near the bottom of the Reflexology page.

Best wishes for your work in reflexology.

Return to List

Using CO2 for supercritical extraction

Physics

January 29, 2017

Question

I would like to discuss some commercial uses for Dry Ice and it's conversion to Co2 for supercritical extraction.
Please let me know if you are available to discuss.

Thank you in advance,

Gary - USA (27838)

Answer

Dry ice is a convenient source of CO2. Allowing the gas from the dry ice to heat to about 31 degree C should help in the supercritical extraction process.

I hope that helps. Unfortunately, I am not an expert in this field.

Best wishes for success in your work.

Return to List

Gravitational force

Physics

January 28, 2017

Question

1. Two objects attract each other with a force of 1×10^-8 N when separated by 20 cm. If the total mass of the objects is 5 kg what is the mass of each?

2. A spacecraft is on a journey to the moon. At what point between these two bodies does the gravitational force exerted on the spacecraft by the earth exactly balance gravitational force divided by the moon? At this point what is the net gravitational force on the spacecraft? assuming no other gravitational forces act.
I'd really love some help figuring these out!! Thank you!

Emily - USA (27831)

Answer

In the gravitational force equation, let "m" equal the mass of one object and "5 - m" be the mass of the other object. Thus, the equation is:

F = G(m)(m-5)/R^2
Thus: F(R^2)/G = m^2 - 5m
Use the quadratic formula to solve for m.
Note that R must be in meters.

See Law of Universal Gravitation for more information.

The second problem is solved by using the forces from the Earth and from the Moon on the spacecraft: GmM/r^2 = GmE/R^2
where m is the mass of the spacecraft, M is the mass of the Moon, r is the distance from the Moon to the spacecraft, E is the mass of the Earth, R is the distance from the Earth to the spacecraft. Also D = r + R the distance between the Earth and the Moon. That involves a lot of Algebra.

The net force is zero, since the gravitational forces cancel out.

I hope that helps.

Return to List

Reducing aerodynamic drag

Physics

January 28, 2017

Question

how to reduce aerodynamic drag

fatmil - Uganda (27833)

Answer

Usually, the shape of the object determines much of the aerodynamic drag. Streamlining can reduce that drag. Also, surface conditions can reduce some of the drag.

See Factors in Changing Fluid Friction for more information.

Return to List

Correcting number of Jupiter's moons

Astronomy

January 24, 2017

Question

On your article about the Earth's Moon, you said the Earth has one Moon and Jupiter has 9 moons. This is incorrect, NASA has recently discovered that Jupiter has 67 moons! I believe the number is up to 67 now. Up until a few years ago, they knew it had at least 63 moons. Galileo discovered 4 of them in the early 1600s. I can only see 5 of them with my modern day, powerful telescope.

David - USA (27823)

Answer

Thanks for the information. I corrected the Characteristics of our Moon page as well as added material on Jupiter and Jupiter's 67 Moons.

Return to List

Motivations for good grades

Grades

January 20, 2017

Question

I understand that many students are motivated in their school work to make their parents happy or prevent them from being angry but this is entirely external motivation. Nothing about this is motivation from inside the student. Nothing about this is visionary and external motivation is not necessarily a useful skill to have is it relies entirely on environmental factors. For these, I don't believe you should promote this type of motivation.

Carter - USA (27816)

Answer

Reasons to Seek Good Grades not only states that one external motivation is to please the parents, but it also gives internal motivations of satisfaction from proving yourself and being able to get into college.

Return to List

Superhero trying to outrun villan

Physics

January 18, 2017

Question

Hi there, I am researching for a comic book and was hoping you could answer a question I have. If an object accelerates in one direction (a) then suddenly reverses applying the same force in the opposite direction (b), is it possible that if travelling fast enough the sudden change in direction (a to b) would have a spring board effect increasing the acceleration and overall speed when continuing in direction (b)? How fast would the object need to be moving? This scene will be set in space and has a superhero character that is trying to find a way of outrunning his counterpart. Many thanks.

Karl - UK (27814)

Answer

Acceleration means that the superhero is continually increasing in speed. This could happen until he reached the speed of light.

If a the same force was applied in the opposite direction, the superhero would slow down until he stopped and then started to accelerate in the opposite direction.

It would be better to suddenly accelerate in a sideways direction, which would fool the villain, who would continue going along until he adjusts his direction of motion.

I hope that helps. Best wishes for your comic book.

Return to List

Wore a PIG pin

History

January 17, 2017

Question

i was a police officer during this time for the city of Kankakee which was a racist dept and we were issued a tie pin with a pig in the middle and words around it said "Pride Integrity Guts. I still have that pin.what happened during my time there you would not believe.

dennis - USA (27811)

Answer

Thanks for sharing your experience. It was good that the police forces turned what was supposed to be an insult into a positive statement.

I see that some of the recent demonstrators have been calling the police "pigs" again. They could stifle that by wearing pins like you had back then.

Return to List

Recommending mesothelioma resource

Health

January 16, 2017

Question

Good afternoon

My name is Virgil Anderson, and I’m a cancer patient at NCI. I saw some information on your site about mesothelioma and asbestos, and I was hoping you had room for mesothelioma.net. The medical professionals behind mesothelioma.net got me into NCI, and have been responsible for my continued battle against mesothelioma. They sponsor The American Cancer Society, ALA, Make a Wish Foundation, MD Anderson and many, many more.

Please, if there’s anything you can do to help, let me know.

I appreciate your time in advance, and hope you’re off to a good start in 2017.

God bless,

Virgil - USA (27809)

Answer

Thanks for the information. I checked an saw that I already have a link to mesothelioma.net. However, I moved it to a more prominent position.

Best wishes for a full recovery from your cancer.

Return to List

Weight of two containers of water

Physics

January 16, 2017

Question

Two containers one of them has water and small piece of wood and another one has only water which one is heavier ?

Misho - Egypt (27810)

Answer

If both containers have the same amount of water in them, then the one with the wood in it would be heavier by the weight of the wood.

However, if the containers were full to the top and the piece of wood was added to one of them, some water would overflow from the container. The weight of the overflow water would be the weight of the water displaced, such that both containers would then weigh the same.

Return to List

Calculating speed of light for spectral line

Physics

January 15, 2017

Question

Hi,
Hope you can help us. We are trying to calculate the velocity of a wavelength using a line profile.
We don't know what we are doing :-(
We know the rest wavelength 36.4680 nm, the line centre is 36.462 nm and c.
The anwser we are getting is 299785064.75!!!
Can the velocity of the wavelength be near the speed of light?
What is the correct formula?

Thank you on behalf of the LYIT astronomy society.

Seamus - Ireland (27806)

Answer

You need to be exact in your terminology. The "velocity of a wavelength" is incorrect. You should be looking at the velocity of light for a given wavelength.
In space, the light travels at the same speed for all wavelengths. When the radiation is passing through a material, the speed varies according to the wavelength or frequency.

If the source of the light is moving, the speed of light remains constant, but the wavelength can shift according to the direction and velocity of the source.

The profile of a spectral line is affected by the various velocities of the particles emitting that specific wavelength. The Doppler Effect causes the slight shifts in wavelength from the ideal situation.

I hope that helps.

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.