Wednesday

August 5, 2015

August 5, 2015

Number of results: 145,229

**math**

Posted by mota THE MASS OF THE SUN IS ABOUT 10^27 METRIC TONS , OR 10^30 KILOGRAMS . HOW MANY KILOGRAMS ARE IN ONE METRIC TON ? ----------------------- math - drwls 1000. ----------------------- explain please i want to understand this question :) this is my question i posted ...
*March 2, 2008 by mota*

**physics-bobpursley/drwls please check**

bobpursley/ drwls please help me with my post on Sunday, April 15 at 10:16pm and 10:19pm. Thanks!
*April 16, 2007 by Mary*

**math**

Posted by mota on Saturday, March 1, 2008 at 3:34am. THE MASS OF THE SUN IS ABOUT 10^27 METRIC TONS , OR 10^30 KILOGRAMS . HOW MANY KILOGRAMS ARE IN ONE METRIC TON ? ----------------------------- math - drwls 1000. ----------------------------- explain please i want to ...
*March 2, 2008 by mota*

**music yr 8- re- drwls**

thankyou drwls for your help on buddy holly
*September 22, 2008 by astra*

**DRWLS,MATH,ALGEBRA**

Drawls, How did you get 2h. and then the 2a/h from.Can you help me understand it when you get a chance. Directions: Solve each literal equation for the indicated variable. A=1/2h(B+b) (For b) Area of a trapezoid For Further Reading math,algebra - drwls, Monday, December 18, ...
*December 18, 2006 by jasmine20*

**Algebra-please check**

Could someone please check my solution-Thank you-DRWLS helped me set it up and I solved it, I think From the top of a mountain 150 feet high, Jessie stands at the safety rail on the edge and looks below. The angle of elevation from his bike on the ground to Jessie is 38 ...
*January 7, 2011 by Joseph*

**Physics check**

A speeder traveling at 41 m/s passes a motorcycle policeman at rest at the side of the road. The policeman accelerates at 3.3 m/s2. To the nearest tenth of a second how long does it take the policeman to catch the speeder? Im sorry I am new to physics this is my first year and...
*July 13, 2010 by Me*

**physics: drwls**

drwls for the question below, the answer seems to be wrong: The four tires of an automobile are inflated to a gauge pressure of 1.8 multiplied by 105 Pa. Each tire has an area of 0.025 m2 in contact with the ground. Determine the weight of the automobile. It asks for the ...
*July 22, 2008 by Elisa*

**math**

3 3/4pt=____c show steps and work please Try the method DrWLS or I showed you FIRST. Repost if you still don't get it but tell us what you don't understand about the procedure.
*November 30, 2006 by brooke*

**Physics**

Two 0.09g pith balls are suspended from the same point by threads 40cm long. (Pith is a light insulating material once used to make helmets worn in tropical climates.) When the balls are given equal charges, they come to rest 19 cm apart What is the magnitude of the charge on ...
*January 25, 2010 by Lanise*

**To: Drwls**

can you please check my previous science post, thanks
*March 1, 2010 by Sara*

**physics**

thanks for the answer drwls. can you please explain to me, how it happened?
*December 4, 2011 by gem*

**Physical Science**

Drwls, would please explain more? I'm not getting this. Thanks
*November 2, 2007 by Sarah*

**To: drwls**

Can you please have a moment to look at my other science post which you helped me on, thanks
*February 8, 2010 by Sara*

**Math**

I got it! Thank for your help, drwls.
*December 10, 2007 by Thanks, drwls*

**physics**

A horizontal segment of pipe tapers from a cross sectional area of 50 cm2 to 0.5 cm2. The pressure at the larger end of the pipe is 1.26 105 Pa and the speed is 0.029 m/s. What is the pressure at the narrow end of the segment? Pa Please help! physics - drwls, Monday, April 9, ...
*April 10, 2012 by Malika*

**Physics**

A horizontal segment of pipe tapers from a cross sectional area of 50 cm2 to 0.5 cm2. The pressure at the larger end of the pipe is 1.26 105 Pa and the speed is 0.029 m/s. What is the pressure at the narrow end of the segment? Pa Please help! physics - drwls, Monday, April 9, ...
*April 10, 2012 by Malika*

**Physics**

A horizontal segment of pipe tapers from a cross sectional area of 50 cm2 to 0.5 cm2. The pressure at the larger end of the pipe is 1.26 105 Pa and the speed is 0.029 m/s. What is the pressure at the narrow end of the segment? Pa Please help! physics - drwls, Monday, April 9, ...
*April 10, 2012 by Malika*

**Math drwls please help**

Derive the basis functions Ni,3(u) and find the equation for the open quadratic B-spline curve defined by five control points p0, p1, p2, p3, and p4. I know the formula is P(u)= the sum of n,i=0(PiNi,k (u)) it's difficult to type the formula in this text box. I hope you can ...
*October 15, 2008 by Mary*

**drwls please check**

Can you please check my physics posts. Thanks!
*November 6, 2007 by Mary*

**Science**

Please drwls solve it for me two equal charges of magnitude 0.00000000032 is placed in an electric field. calculate the force of attraction between them
*November 5, 2012 by Drift*

**Algebra-drwls please check!**

Posted by Megan on Tuesday, October 12, 2010 at 3:44pm. I have a question if someone could help, please explain it. Given b = -1 and h = -1, what is the equation of the graph if the parent function is y = sqrt (x) Answers: a.y = sqrt(x-1) b.y = sqrt (-x+1) c.y = - sqrt (-x-1) ...
*October 12, 2010 by Megan*

**MATH**

Thanks for the answers but I must show the work for each problem. Can someone please help now that I finally submitted the square root correctly,thanks to drwls, and Ms. Sue. Thank you The slash (/) line represents that the number is a fraction. divide: sqrt45 / sqrt81 = ...
*October 29, 2011 by PLEASE HELP*

**HEY DRWLS!! I have a question**

You're a genius, so can you please help me with my advanced algebra question. I posted it down below!! Thanks:) Miley
*January 29, 2008 by Miley*

**drwls history**

please could i say a huge thankyou you have helped me alot and i appreciate it thankyou again you are a star! :]
*October 17, 2010 by kellie*

**math**

Thank u drwls n u obakeng now plz factorise this one. 25x^2-25xy+6y^2
*February 25, 2011 by Tshepiso mphehlo*

**To drwls**

I posted some Physics questions yesterday, but no one got the chance to look at them, so can u please go to 2nd page and look through them.
*November 23, 2010 by Anabelle*

**physics **

DRWLS: PLEASE SEE ADDITIONAL INFO AT THE BOTTOM its the second part of the question that I don't understand: according the graph shown, the net force acting on an object varies wth the object's displacement. Calculate the work down by the force on the object at the various ...
*January 30, 2010 by Sarah N H*

**math. HOW DO I CONVERT A DECIMAL TO A FRACTION**

how do i convert a decimal to fraction in SIMPLEST FORM? a) -2.756 ?? Write out the 0.756 as 756/1000, then reduce it to lower terms if you can. Since both numerator and denominator are evenly divisible by 4, 756/1000 can be reduced to 189/250. The mixed number becomes -2 189/...
*February 25, 2007 by sarah*

**Physics**

A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed by 3.0 cm in bringing the block to a momentary...
*April 6, 2007 by Mary*

**Calculus: drwls, please**

First, I appreciate your help, and this is very kind of all of you to help us. Now, this problem we are both sick of: we are to use transformations of f(x)= 1/x or f(x)=1/x^2 to graph the rational function: f(x)= 1/x -4. I tried using the information you gave me, but my graphs...
*April 4, 2008 by Pam*

**Math(Geometry)**

To Lauren - Ms. Sue, Monday, September 28, 2009 at 10:24pm What post? What is your question? In addition, your "name" can not be HELP ME NOW!!!! No one appreciates being screamed at to help you now! Using all caps online is like screaming at us. To Lauren - HELP ME NOW!!!!, ...
*September 28, 2009 by Mr.Sonyericson*

**math**

2Tons=____oz Try the method DrWLS or I showed you. Then repost if you don't understand but tell us what you are having trouble with.
*November 30, 2006 by brooke*

**Singapore Math**

Thanks "drwls" but do you know how to solve that problem using the bar model method? I know what the answer is. I just don't know how to draw it like you do in Singapore math. Thanks...
*December 12, 2012 by Ashli*

**Physics- drwls please help**

A certain CD has a playing time of 80 minutes. When the music starts, the CD is rotating at an angular speed of 4.8 x 10^2 revolutions per minute (rpm). At the end of the music, the CD is rotating at 2.1 x 10^2 rpm. Find the magnitude of the average angular acceleration of the...
*March 14, 2007 by Mary*

**geography**

i donot understand your answer drwls actually i feel difficulty in this project.please give me a hint how i prepare this and ialso feel difficulty in making pie chart
*January 9, 2012 by seibt*

**math**

solve for y? z=0.3(y-6)^2 please can you explain your working, Many thanks, Wendy. * Algebra - drwls, Friday, November 20, 2009 at 9:40am (10/3)z = (y-6)^2 y = sqrt[(10/3)z] +6 = 1.826 sqrt z + 6 * Algebra - wendy, Friday, November 20, 2009 at 9:47am I'm sorry. Really don't ...
*November 20, 2009 by wendy*

**math help**

did anybody answer my question drwls answered your geometry question.
*October 3, 2006 by jessica =]*

**physics**

thank you for your help drwls
*January 27, 2008 by Charles*

**DrBob222 please check**

DrBob222 please check my physics question posted at 8:55pm. The subject is drwl please check. I am not getting a response from drwl. Thanks! Mary DrWLS is not on right now. My physics is too poor to trust my answers. Bob Pursley is smarter than I am; he does physics, math, and...
*February 27, 2007 by Mary*

**MATH!!!PLEASE HELP!!**

A wall is supported by a brace 10 feet long. If one end of the brace is placed 6 feet from the base of the wall, how many feet up the wall does the brace reach? Think of the right triangle frmed by the wall, the floor and the brace, and use the Pythagorean theorem. The brace ...
*February 27, 2007 by megan*

**TO DRWLS/MATH HELP PLEASE**

How do i solve inequalitites with three variables. I still can't figure it outplease help. x+y=1 y-z=-3 2x+3y+z=1 THE ANSWERS ARE X=3,Y=-2,Z=1 i KNOW THE ANSWERS I JUST DON'T KNOW HOW THE BOOK GOT THE ANSWERS . i 'VE TRIED MANY DIFFERENT WAYS AND I STILL DONT' UNDERSTAND IT ...
*October 22, 2006 by Jasmine202005*

**drwls**

Thank you very much.
*March 6, 2008 by Pam*

**physis**

to DRWLS thanks for the help DEEK./
*May 23, 2011 by DEEK*

**material engineering**

Thank you so much drwls ... please, Do you mean is also possible to choose tin-coated steel for (Beverage cans)? Because it is required to choose more than one metal and compare them in terms of cost, attributes and manufacturing process, and then chose the most appropriate.
*March 7, 2011 by hym*

**DRWLS**

THANKS WHAT IS WRONG WITH ESTAR IN NUMBER
*November 8, 2007 by sam*

**Physics**

In my last post, I'm confused how drwls got P2/P1 = 14.8
*January 8, 2009 by Phil*

**drwls **

thankyou for your help its helped me alot you are a star!
*October 6, 2009 by dominique*

**physics**

anyone who knows the answer to this question please show your work. drwls i know i posted this queestion before but you didnt reply to my comment. Your friend has climbed a tree to a height of 6.00 m. You throw a ball vertically up to her and it is traveling at 5.00 m/s when ...
*December 21, 2010 by sabeen*

**Math**

I posted these 2 questions a couple of days ago and although the help I received would have been more appreciated if it didn't come with an underhanded comment, I did see where I made my mistake with the first question, however I would like to know with the second question, ...
*November 20, 2010 by Dania*

**math**

Drwls - totally confused me on how this problem is done. Can someone else help to solve this problem? If two numbers are relatively prime, what is their LCM? Explain the reasoning and give 2 examples supporting the answer.
*March 26, 2011 by Brandon*

**TO drwls**

I just wanted to say THANK YOU so much. You're a lifesaver!
*February 22, 2008 by Shirley*

**drwls**

Thank you for your help, & for the website, makes for some interesting reading.
*March 31, 2008 by TJ*

**algebra**

thanks drwls i have the correct answer thanks again :)
*May 6, 2010 by kiddo*

**drwls,math**

so you are saying that i should label p = 30 i = 0.0125/12 = 0.0010416666666666666666666666666667 n = 12(3) = 36 then plug it into what formula ? Problem: Stereo shack sells a stereo system for $600 down and monthly payments of $30 for the next 3 yrs. In the interest rate is 1...
*June 22, 2007 by student*

**drwls-year8 geography**

thanks for finding that link its helped me with my homework
*January 27, 2009 by AMIE*

**Physics**

True/False 1)Specular reflection obeys the laws of reflection while diffuse reflection does not. False. drwls said its true but I disagree can you please explain. 2)A convex lens is used to obtain an enlarged virtual image. True.
*April 8, 2008 by Jon*

**9th grade algebra**

drwls here is another one of those questions like the last one we submitted if this will help with what they are after. 200 dollars/1 ton x 100 cents/1 dollar x 1 ton/2000 pounds x 1 pound/16 ounces could you please show me how you come up with the answer? I am not sure how ...
*April 9, 2009 by Dippy*

**For drwls**

I reposted again down below, if you wouldn't mind looking. Thanks, much appreciated :)
*June 28, 2008 by Casey*

**drwls + Ms Sue geog yr 8**

thanks so much to both of you for finding the websites they have helped alot.:)
*March 13, 2009 by misha*

**Physics**

Thanx DRWLS! Worked like a charm and I checked behind myself with the same formula!!!
*November 16, 2009 by Inascent*

**physics**

Good job "Drwls", your answer to my bowling ball question worked. Way to go!
*March 17, 2010 by norm*

**math**

6a^2+4a+5+3a^2+7a-2 That is the same thing as 9a^2+11a+3, but what is the question? You have just written an algebraic expression, not an equation to be solved. assuming you are required to factorise the equation and the expression give by drwls it factorises to (9a+3)(a+1) ...
*January 26, 2007 by chucke*

**Science-drwls**

Y r the distances to the planets given in km? I've already answered the 2nd part to this question, and this is the fist part. I think that the distances to the planets are given in kilometres because all the planets aren't that far away from eachother that they need to be ...
*February 22, 2010 by Sara*

**English**

Posted by rfvv on Thursday, December 16, 2010 at 3:21am. {At a restaursant} For hear or to go? Is this for here or to go? It's for here, please. It is to go, please. (Are the expressions above all grammatical? What is the meaning of 'is to' in 'It is to go, please.'? Does it ...
*December 16, 2010 by rfvv*

**physics**

for some reason, choice 6 was incorrect when i tried it sorry to keep bothering you about it drwls
*February 20, 2010 by from previous question*

**drwls, math**

Did you mean the following for the problem: 10) perform the indicated operations 3 and 3/4 (divided by ) 1 and 3/8 . 3 3/4 - 1 3/8 . 15/4 (divided by ) 11/8= 30/11 =(after rounding it should be 2.73) thats how it suppost to be and look Yes, that is what I meant. You never said...
*November 26, 2006 by Jasmine20*

**ATTN: DRWLS RE: PHYSICS**

pete and john play a game of tug f war on a frictionless icy curface. pete weighs 539 N and john weights 392 N. during the course of the game, john accelerates toward pete at a rate of 3 m/s^2 a)what's the magnitude of the force that peter exerts on john? b)what's the ...
*January 23, 2010 by samir*

**math**

Whatwould be the answer 3+9+6+52x963+??? The answer depends upon where you put the parentheses. The order of operation makes a big differnece The answer depends upon where you put the parentheses. The order of operation makes a big differnece I agree with drwls...... But, ...
*February 23, 2007 by Crystal*

**Chemistry**

drwls, if you are there, I got an answer of 42.5 Kelvin, so then that means it is a negative number if converted to degrees Celsius? Question: The heat capacity of a bomb calorimeter is 87.5 kJ/K (this value is for the total heat capacity including that of the water jacket ...
*December 12, 2007 by Anne*

**algebra**

Can someone help me with this problem please? rationalize the denominator and simlify the answer: 5/2 + the square root of 3 Do you mean 5/(2 + sqrt 3) ? What you wrote could also be interpreted as 2.5 + sqrt 3. You need to be more careful to use parentheses when necessary to ...
*March 1, 2007 by Maria*

**drwls & Damon - maths**

hey guys, i follow you up to the point of intergrating the final line. How would I intergrate [x^-2.e^-x] dx thx
*December 29, 2007 by xX_Supaman_Xx*

**physics**

a 2.5 kg rifle fires a 20 g bullet at 400 m/s. What is the magnitude of the recoil velocity of the rifle? I still don't understand. Could you please help with a formula? Thank you. physics - drwls, Monday, February 7, 2011 at 6:38pm Try using conservation of momentum. recoil ...
*February 7, 2011 by Sejul*

**Math**

What is the value of y if x = -3? y = 1 = 2(x-5) Plug in -3 for x, in the equation for y, and see what you get. I think you copied the problem wrong. Is the first = sign supposed to be a + or - sign? If not, you have already stated that y = 1. That cannot be true when x = -3. ...
*June 29, 2007 by Ruby*

**physics - another question**

Sam is sitting in her fishing boat watching a trout swim below the surface. She guesses the apparent depth of the trout at 2.0m. She estimates that her eyes are about 1.0 m above the water's surface, and that the angle at which she's observing the trout is 45 degrees. b) ...
*January 16, 2010 by Sarah N H*

**One for drwls**

Thank you for answering my question. Can you steer me to making a quadratic from 1/4(x+3)^2-4 Then I can get the intercepts. Thanks Just multiply it out to put it in the standard form, ax^2 + b^2 + c (1/4)(x+3)^2-4 = (1/4)(x^2 + 6x + 9) -4 = (1/4)x^2 + (3/2)x - 7/4 You're a ...
*March 21, 2007 by charlie*

**Maths**

Thanks for the help DRWLS. I tried to work is out and came up with this working out: A(4,-2) is parallel to 2x-3y=7 y = mx + c -3y = -2x + 7 y = 2/3x - 2 1/3 (y-y*) / (x-x*) = m (y+2) / (x-4) = 2/3 y+2 = 2/3(x-4) y+2 = 2/3x - 2 2/3 y = 2/3x-2 2/3 - 2 y = 2/3x-4 2/3
*March 15, 2008 by Mel*

**re-drwls-geography**

thanks for your help i would have labelled my question geology but it is for geography sorry
*February 8, 2011 by polly*

**urgent!!!words questions**

I have alot of questions here but you don't have to answer them all but please help me!They are due on 24/6/05. The male of mare? The citizens of Paris,Netherlands,New Zealand or Malta? The collection name for cattle,wolves,lions,elephants or whales? What animal make a sound ...
*June 22, 2005 by Sandy*

**DRWLS**

cAN YOU LOOK AT THE PREVIOUS POST. i am completely lost towards that equation...how do i even solve it because then i would have to cross multiply or cancel and that will give me zero.
*February 25, 2007 by jas20*

**Physics**

During an action potential, Na^+ ions move into the cell at a rate of about 3x10^-7 mol/m^2*s. How much power must be produced by the "active Na^+ pumping" system to produce this flow against a +30-mV potential difference? Assume that the axon is 40cm long and 30um in diameter...
*February 12, 2013 by John*

**Physics repost**

Please help!! I have tried everything and is still coming up with and incorrect answer. A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.70 T in a time of...
*October 10, 2007 by Mary*

**Physics(Please respond)**

A golfer hits a shot to a green that is elevated 3.0 m above the point where the ball is struck. The ball leaves the club at a speed of 17.4 m/s at an angle of 35.0ĒŠ above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air resistance...
*May 29, 2012 by Hannah*

**PHYSICS!!!**

A 0.30-kg softball has a velocity of 12 m/s at an angle of 30° below the horizontal just before making contact with the bat. What is the magnitude of the change in momentum of the ball while it is in contact with the bat if the ball leaves the bat with a velocity of 17 m/s, ...
*February 24, 2007 by winterWX*

**Physical Science (repost for drwls)**

OK, I've been trying my best and for 3 I got B and for five I got B...? 4 still seems really tricky to me! -MC
*May 3, 2009 by mysterychicken*

**trigonometry**

Find the distance using the appropriate arch length. A television tower 520m high subtends an angle of 2deg30'. How far away is the tower? some people that helped me alot were Reiny, Damon, bobpursley, and drwls..so i just wanna say thnks to you guys...are u guys math expersts...
*January 16, 2009 by y912f*

**Physics(Please respond)**

1) A cave explorer drops a stone from rest into a hole. The speed of sound is 343 m/s in air, and the sound of the stone striking the bottom is heard 1.33 s after the stone is dropped. How deep is the hole? I did 343 / 1.33. Is this correct? Physics(Please help) - drwls, ...
*May 27, 2012 by Hannah*

**Physics repost please check**

A glass bottle of soda is sealed with a screw cap. The absolute pressure of the carbon dioxide inside the bottle is 1.80 x10^5pa. Assuming that the top and bottom surfaces of the cap each have an area of .0004M^2, obtain the magnitude of the force that the screw thread exerts ...
*April 9, 2007 by CJ*

**drwls, or other tutors**

does my last postage seem correct for the answers that i got. The one that doesn't have a reply. See previous reply to your post.
*March 1, 2007 by jas20*

**Please check my solution bob pursley or drwls if a**

If I had the old-fashion camera that had a focal length of 35mm(0.035m) and I take a picture of a person 6 m away, how far does the film need to be from the lens to record a clear image? I know that the equation is 1/f = 1/d(object) + 1/d(image) so would I do the following: 1/...
*February 13, 2011 by Robert O.*

**drwls, math ,algebra**

should i take then away the 1, and 16 from the question of the listing all the factors of 16. so i should leave it as: list all the factors of 16: 2,4,8 I would leave out 1 and 16, since the pair is obvious and does not divide up the number 16 into smaller integers. I can't ...
*December 17, 2006 by jasmine20*

**drwls, math**

Let me know if i got it correct. for the problem: When x number of units are sold, the price of each unit (in dollars) is given by p =-x/2 +75 . Find the unit price when the following quantities are sold: 2,7,9,11. My answer: for 2= you gave me the answer of $74 This is what i...
*December 22, 2006 by jasmine20*

**drwls i replied!**

i replied and I answered below.
*November 7, 2006 by Francheska*

**for: drwls -Dr.Russ**

Is there a 'Dr.Russ' that can help with Organic Chem?
*March 12, 2008 by K*

**drwls, is this correct,math**

drawls this is from the previous post is this correct. solve the system by subtraction. 5x-3y=13 4x-3y=11 equation#2 woudl be 4x-3y=11 -3y = -4x+11 y = (4)/(3) x - (11)/(3) so now i substitute it to equation #1 5x - 3((4)/(3)x - (11)/(3)= 13 5x - 4 x +11 = 13 1x + 11 = 13 1x...
*February 13, 2007 by jasmine20*

**Physics to drwls question to answer given earlier**

A 0.700-kg ball is on the end of a rope that is 0.90 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 70.0° with respect to the vertical as shown. What is the ...
*February 17, 2012 by Angelina*

**prealgerbra**

how do you solve 45 min/2 mi=?h/1 mi pre algerbra - drwls, Friday, January 6, 2012 at 11:44pm If you go 2 miles in 3/4 hour, you go 1 mile in 3/8 hour (or 22.5 minutes). how do we show are work then
*January 7, 2012 by steph*

**Physics-please check-this can't be right**

I asked about a golf ball hit at a 35 degree angle and the hole was 175 m away. What was speed of ball. I got a response, and it follows with my response. I'm not doing something right, can you help, please.Physics - drwls, Saturday, October 9, 2010 at 10:20am You can come up ...
*October 9, 2010 by Anthony*

**DrRuss/bobpursley/drwls please help!!!**

Can you please clarify your response to my post Wednesday April 4th at 8:53pm and 8:54pm. Thanks for all of your help!!! pleasde repost it. Yes, repost it. Go to it, copy, and paste it here. Thanks. A vertical spring with a spring constant of 450 N/m is mounted on the floor. ...
*April 6, 2007 by Mary*

**Physics- drwls please help**

(a) Calculate the kinetic energy that the earth has because of its rotation about its own axis. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States in one year is about 9.33 109 J. (...
*March 28, 2007 by Jim*