Monday
September 22, 2014

Posts by Leo


Total # Posts: 373

test
Somebody messed up the list of banned IPs. When you have an IP to ban, please e-mail it to me for now. Thanks!
January 9, 2008

math
HINT: numerator is always 1 denominator is always...
January 8, 2008

Maths ..Equations
I understand..and thank you for your help !! :-)
December 10, 2007

Maths ..Equations
Hi I have to rearrnge the following to make y the subject.. x = 3 - 2y / 6 I get the first part do x 3, - 2, and / 6. Undo x 6, + 2, and / 3 then multiply by 6 so, 6x = 3 - 2y add 2 to both sides, 6x + 2 = 3 the divide both sides by 3 6x + 2 = y ------- 3 so y = 6x - 2...
December 10, 2007

Quadratic equation..
Thank you for your time and expertise and it does look better on paper ...:-) than the way I typed it here Thanks again !!!!
December 4, 2007

Quadratic equation..
Hi Can anyone tell me if this is correct X Sq - 4x - 16 = 0 using X = -b + Sqrt b sqrd - 4ac / 2a a =1, b = -4 , C = -16 x = -(-4) Sqrt (-4)sq - 4 x 1 x -16 / 2 x 1 = 4 + - Sqrt 80 = 9 + or minus 8.944/2 + = 4 + 8.944 = 12.944/2 = 6.472 - = 4 - 8.944 = - 4.944/2 = - 2.472 I ...
December 4, 2007

In Need of a Mathmetician!!!!
Hint: Write the formula for its movements in the x direction only. Also write the formula for its movements in the y direction. Both of your equations will have limits. Your coordinate solution will be the limits as the ant moves an infinite number of times.
December 3, 2007

Quadratic equation...
Hi Can anyone help me solve the quadratic equation for the following:- The motion of a two stage rocket is stated by it height y in metres above the ground since t seconds since launch. Flies vertically Ist stage burns for 5 seconds and cuts out. 2nd stage rocket is under ...
December 1, 2007

Ti-83 - Motion equation
Hi I have spent ages trying to work out the way to program my TI-83 calculator to solve the following... I would appreciate guidance or direction to a site that can show me how to solve the following;- motion of two stage rocket is stated by it height y in metres above the ...
November 26, 2007

TI 83 Graphing help !!!
Hi I have spent ages trying to work out the way to program my TI-83 calculator to solve the following... I would appreciate guidance or direction to a site that can show me how to solve the following;- motion of two stage rocket is stated by it height y in metres above the ...
November 26, 2007

Equations
Thank you very much
November 25, 2007

Equations
Can anyone check this equation out for me please... another way of writing out... ( 4 + b ) ( 3b - 2 ) is it 12b - 8 + 3bsq - 2b which is 3b sq + 10b - 8 Help appreciated !!! Thank you :-)
November 25, 2007

Science
A student finds that it takes 0.20s for a ball to pass through phototogates placed 30 cm apart on a level ramp. The end of the ramp is 92 cm above the floor. Where should a coin be placed so tnat the ball strikes it directly on impact with the ground?
November 12, 2007

algebra
Thank you !!!
November 11, 2007

algebra
Simplify by expanding the following expression 9 - 6p ------- + 4 3 is the answer, 3 - 2p ------ + 4 3 If not were am I going wrong please Thanks !!!
November 11, 2007

Algebra
Can anyone please check the following for me please Expand (5 - 2x) Squared (5 - 2x) (5 - 2x) 5 sqrd + 5 X - 2x + -2x x 5 + -2x X -2x so 5 Sqrd - 10x - 10x + 4X = 5 sqrd + 4x Am I right..thank you :-)
November 8, 2007

science
we are working at an assembly plant making wooden toy giraffes. At the end of the line,the giraffes go horizontally off the edge of the conveyor belt and fall into a box bellow.If the box is 0.6 m below the level of the conveyor belt and 0.4 m away from it,what must be the ...
November 6, 2007

Maths ..equation
Is this right please .... 3( y - 4 ) - 2 ( 5 - 6y ) = 3 x y = 3y, 3 x - 4 = - 12 -2 x 5 = -10, - 2 x -6y = - 12y Therefore, 2y -12 -10 -12y If I am wrong can you advise where I am going wrong .Thanks !!!
October 24, 2007

maths
Thank you ..I see where I am making my mistake ..THANK YOU !!!!
October 24, 2007

maths
Simply by expanding any brackets and collecting like terms 5x - 2 - 2x + 3 is this 5x - 2x = 3x 2 + 3 = 5 therefore 3x - 5 if wrong please explain Thanks....
October 24, 2007

Chemistry
do I just change the 18cm's to 180mm to help work this out? Would it look something like this: Pressure gas = 180mmHg+0.95atm/760mmHg? 180.95mmHg/760mmHg = 0.238atm?? I think I am way off.
October 21, 2007

Chemistry
What is the pressure (in atmospheres) of the gas inside the container connected to an open-end, mercury-filled manometer as shown in the picture? The atmospheric pressure is 0.95atm. l----l | (G) l | l - --- l Hg l Hg *18cm - - --- Hg Hg HgHgHgHg what process do I use to solve...
October 21, 2007

Chemistry
the picture didn't work. it is U shaped with Hg in the middle and an open end. The distance between the Hg, under the open air portion is 18cm, which is before the bottom of the U. Does that make sense. Basically a manometer.
October 20, 2007

Chemistry
What is the pressure (in atmospheres) of the gas inside the container connected to an open-end, mercury-filled manometer as shown in the picture? The atmospheric pressure is 0.95atm. l----l | (G) l | l - --- l Hg l Hg *18cm - - --- Hg Hg HgHgHgHg what process do I use to solve...
October 20, 2007

Chemistry
I had picked up on that, thank you. I had that answer before but thought it was wrong.
October 20, 2007

Chemistry
so g/mol of oxygen has nothing to do with solving??
October 20, 2007

Chemistry
A closed container is filled with oxygen. The pressure in the container is 435kPa . What is the pressure in millimeters of mercury? (i know that 1atm=760mm Hg=101,325 Pa) How do I use this to solve for the question? so: 435kPa*101,325=44,076,375Pa, & O2 = 32g/mol & you must ...
October 20, 2007

chemistry
Sulfuric acid dissolves aluminum metal according to the following reaction: 2Al(s) + 3H2SO4(aq) -> Al2(SO4)3(aq) + 3H2(g) Suppose you wanted to dissolve an aluminum block with a mass of 15.9g . A)What minimum mass of H2SO4 (in g) would you need? [***A=86.7g***] B)What mass ...
October 20, 2007

chemistry
ignore this question
October 20, 2007

chemistry
For each of the following acid-base reactions, calculate the mass (in grams) of each acid necessary to completely react with and neutralize 3.60g of the base. 2HNO_3(aq) + Ca(OH)2(aq) -> 2H_2O(l) + Ca(NO_3)2(aq) H_2SO_4(aq) + 2KOH(aq) -> 2H_2O(l) + K_2SO_4(aq) how do i ...
October 20, 2007

Chemistry
thank you.
October 1, 2007

Chemistry
ok...so I took 30,000g * 1/120.913g/mol = 248.1122g. Then I went: 248.1122g * 70.906g/mol & got: 17592g = 18kg. Does this look correct? should I carry it through to the rest?
October 1, 2007

Chemistry
How many kilograms of chlorine are in 30kg of each of the following chlorofluorocarbons (CFC's)? CF2Cl2 -in kg's; CFCl3 -in kg's; C2F3Cl3 -in kg's?
October 1, 2007

chemistry
how many oxygen atoms are in 1.60g of quartz - SiO2? how do you figure out atoms to grams and visa versa? the weight of 1 SiO2=60.0848g/mol. please help
October 1, 2007

chem
Question: The American Dental Association recommends that an adult female should consume 3.0mg of fluoride (F-) per day to prevent tooth decay. If the fluoride is consumed as sodium fluoride (45.24% F), what amount of sodium fluoride contains the recommended amount of fluoride...
October 1, 2007

computer programs
I have a problem just getting started on writing pseudocode or a program for the following problem: A worm is moving toward an apple. each time it moves, the worm cuts the distance between itself and th eapple by its own body length until the worm is close enough to enter the ...
September 28, 2007

grammar - showed versus shown
Which is the following sentences is grammatically correct? "She had shown me so much about love." "She had showed me so much about love." Thanks, Leo (webmaster)
September 27, 2007

womens studies
The word "ranking" suggests hierarchy: first rank, second rank, etc. The first rank is "higher" than the second rank. Therefore gender ranking implies one sex is higher or better than the other.
September 25, 2007

iphone
how cool is the iphone
September 19, 2007

Algebra 1
You should set up some formulas using x and y, x being the smaller number and y being the larger.
September 13, 2007

Algebra 1
First, multiply both sides of the first equation by negative one. Then, add the two equations together. This will cancel the y's and you can solve for x.
September 13, 2007

math
Hint: combine two two's so you have a 22 in the equation
September 2, 2007

economics
In economics, ineslasticity is the opposite of elasticity. This article may help you: http://en.wikipedia.org/wiki/Elasticity_(economics)
September 2, 2007

???
I optimized the forum's pages so that archived pages load faster. Also, I optimized individual messages so that they load faster and use up less disk space.
August 24, 2007

???
I am working on the database now :-)
August 24, 2007

time management
As I spend more and more time working, I spend less time with family and friends. However, my career and financial success are important to me. How do I balance the time I spend making money versus time I spend with people? What are some critical questions I may want to ask ...
August 23, 2007

Funny
You are correct. I am working to restore this.
August 22, 2007

Literature
I am currently working on restoring the database. Thanks, Leo
August 22, 2007

Math
uh oh if pencils cost 20 cents and pens cost 30 cents each find the cost of the following items number 36 has r pens and p pencils
August 21, 2007

MATH
Isopropyl alcohol, C3H8O, is used in rubbing alcohol mixture. Alcohol on the skin cools by evaporation. How much heat(in kJ) is absorbred by the alcohol of 2.25g EVAPORATED? THE HEAT VAPORIZATION OF Isopropyl alcohol is 42.1 kJ/MOL Compute the number of moles of C3H8O that ...
June 11, 2007

if you're in the mood for riddles
The riddle forum is back up: http://www.jiskha.com/net_riddle There are some truly clever riddles being posted. The following is one of my favorites. Try not to scroll down because then you'll see the answer(s): http://www.jiskha.com/net_riddle/display.cgi?id=1169785254
April 11, 2007

new description for jiskha.com
The new meta description for jiskha.com is: Students get free homework help from teachers and experts on message boards and chat rooms. Website also features educational articles in math, science, social studies and literature. It will probably take Google a couple weeks to ...
January 25, 2007

description for Jiskha.com
A few of you have noted that Google's description of jiskha.com is ineffective on the search results. It currently reads: ----- Articles, games, humor and puzzles for many school areas including art, computers, English, foreign languages, health, home economics, ...
January 24, 2007

Econ
What effect do lifting of price controls have on inflation in the long run? I need some ideas... I think inflation will eventually be under control in the long run, but i don't know what factors will cause that. Good tough question. Take a shot. I would think that lifting ...
January 21, 2007

Inflation
What long term effect do lifting of price controls have on inflation? This is a debatable issue. What does your book say? What do you think? Will inflation increase in the short run but then eventually decrease because when prices are too high, nobody is willing to buy?
January 20, 2007

trigonometry
Hint: The total of angle measurements inside any pentagon is the same. Hint: Look up the mathematical definition of an arithmetic sequence. IF THE MEASURES OF THE ANGLES OF A PENTAGON FORM AN ARITHMETIC SEQUENCE, WHAT ARE THE GREATEST AND LEAST MEASURES EACH ANGLE CAN HAVE? ...
January 10, 2007

how to sketch a graph of..
Local minimum and local maximum imply that the function approaches negative and positive infinite at opposite sides of the graph. Local minimum (1,1) and local maximum (3,3) means the slope of the function is 0 at these points. Thank you so much. So 1)when the local minima is...
November 5, 2006

school supplies
We just added a number of articles: http://www.jiskha.com/school_supplies This is one of my favorites: http://www.jiskha.com/school_supplies/staples.html Very nice!! =)
October 30, 2006

new forum up and running
The new forum is live. No more random error messages. Much faster searches, sorts and queries. Have a nice day. Thank you, Leo! The new forum is great!
October 29, 2006

one-third done with new forum
I worked on the new forum all day yesterday. It should be done by the end of tomorrow. There won't be any visual changes, but the forum should load even faster. Also, that silly random error message will stop occuring. Wonderful! Keep up the good work. DAG We ALL ...
October 26, 2006

random error messages
Sometimes when posting a new message, a software error will occur with an "unable to post" warning. Right now I am working on fixing this error message once and for all. In the meantime, if you get this message, hit refresh on your browser to try to post the message ...
October 25, 2006

message board threads
As you may have noticed, an entire thread can now be viewed by accessing the original message. I think this is great for students, and this may enhance search engine rankings. If anyone has serious objections to this, please let me know. Thanks, Leo I think it's wonderful...
October 24, 2006

open-ended formatting tags no longer an issue
If you forget to end your bold or italic tags, this is no longer an issue. All formatting tags are terminated at the end of each post. Tags currently allowed for anyone to use are b, i, u, sup and sub. example It is still good practice, however, to pair each opening tag with a...
October 24, 2006

I think we're doing something right
I noticed a few things: 1. when I search for homework help on Google, we're #10 (page 1)! 2. We received so many homework questions yesterday that page 1 and 2, and half of 3, was filled up with questions from Thursday. 3. 99% of the students who post are receiving GREAT ...
October 20, 2006

subscripts and superscripts enabled
Examples: The water molecule: H20 Quadratic: ax2 + bx + c = 0 Just like you would use the b tag for bold or the i tag for italic, use the sub and sup tags for subscript and superscript. that's great...but what do you mean "b tag" and "i tag" ?? the b ...
October 12, 2006

how can we improve jiskha.com?
How can we improve jiskha.com? Any ideas for improvement are welcome. Thanks! Perhaps separating the subject areas. The subject area categories could be fairly general: English, including how to research Mathematics/economics Sciences Social studies/history Foreign languages ...
October 12, 2006

search box on jiskha.com
The search box at the top of this page now searches the entire jiskha.com forum in real time. http://www.jiskha.com/search/search.cgi?query=apples Nice. very nice.
October 11, 2006

5th grade math
what is the least common multiple The least common multiple is the lowest possible number that has both numbers for a factor. For instance, if you are asked to find the LCM for 4 and 8, the LCM would be 8 because it is divisible by both 4 and 8. If you were given 3 and 4, the ...
October 5, 2006

grammar
Does the following sentence contain any grammatical errors? Those are the kinds of people whom I will never talk to. Thanks, Leo Although it ends with a preposition, which some purists consider poor form, I see nothing wrong with the sentence. It also used "whom" ...
August 9, 2006

homework help ranking
When I search for homework help on google from my computer, jiskha is ranked at #14. What is jiskha ranked on your computer? Thanks. Jiskha came in 12th on my computer. About 14 with or without " " Probably because of lower use during summer? 14th here -- and I think...
July 16, 2006

#2 on msn
I just noticed that if you search for homework help on m.s.n, we're number 2. ... and #8 on Google! =) # 4 on Yahoo And #1 with me. For a couple weeks now, if I search for homework help on my own connection, jiskha is ranked at #11 or #12. But if I go to the library, ...
June 28, 2006

new data type for forum
Currently the forum uses hash maps which becomes extremely complex and prone to glitches as the number of posts approaches 10,000. I have determined that one solution would be to use linked lists instead of hashes. In fact, linked lists, also known as threads, is what most ...
June 20, 2006

annual salary
What is the formula to determine someone's annual salary given only the hourly wage? For example, if someone works full time for $20 per hour, how much does he earn in a year? A friend of mine told me the formula before; it's really simple. I just forgot it. Thanks! If...
June 13, 2006

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