Science & Mathematics - 11 February 2007

Suppose a ladder of length L is leaning against a frictionless wall. The top of the ladder reaches a point that is y units from the ground. The bottom of the ladder is x units from the wall. The bottom of the ladder is moving to the right with speed v. Therefore x and y are quantities that change with time. By the Pythagorean Theorem x^2+y^2=L^2. Solving for y gives √L^2-x^2 . Differentiating both sides with respect to time gives dy/dt= -x( √L^2-x^2) (dx/dt). But dx/dt=v , so dy/dt=-xv/√L^2-x^2 . As x approaches L, the numerator approaches -Lv (a nonzero negative number) while the denominator approaches 0. Hence, the quotient is going to negative infinity. In other words, the top of the ladder is falling infinitely fast when the bottom of the ladder has been pulled a distance of L from the wall.

2007-02-11 04:13:47 · 4 answers · asked by bala7425 1 in Mathematics

2007-02-11 04:13:22 · 6 answers · asked by Anonymous in Other - Science

2007-02-11 04:12:47 · 5 answers · asked by kittysam13 1 in Other - Science

1/2 x - 1/3y = 5/6
- 2/5x + 1/2 y = - 9/10

2007-02-11 04:12:12 · 6 answers · asked by markbernetie 1 in Mathematics

I often ask on here, when did time begin, I know that no-living thing can answer this question. People tend to say that it has no beginning, and I question them "how could something with no beginning exsist?"
People come up with the conclusion statement that human minds can't grasp the concept of there not being a beginning...
But although our puny human minds can't grasp it, mathematically and theoretically, it's impossible for something to have NO origin.
People say that the big bang created time, that's impossible. What was before the big bang?

When I think deeply about this life.. and the general beginning of time, like I mean trillions and trillions and trillions.. ect of years ago BEFORE the big bang, it leaves me awestruck and sometimes I come up with the conclusion that life is nothing but a mere illusion, that only I AM experiencing, it's mind boggling and quite scary to think about

Your thoughts?

2007-02-11 04:12:10 · 6 answers · asked by Anonymous in Physics

2007-02-11 04:10:55 · 4 answers · asked by tray j 1 in Mathematics

why the pattern of atomic radii in the periodic table? (move down in a family, or group, it increases, move across a period and it decreases.) does it have to do with the structure of the atom and atomic mass?

2007-02-11 04:09:20 · 5 answers · asked by dreamer 2 in Chemistry

2007-02-11 04:09:12 · 9 answers · asked by tray j 1 in Mathematics

2007-02-11 04:09:01 · 3 answers · asked by ~ ♥ ~ 2 in Medicine

how do i save myself when the water actually comes rushing down my house.
i know it not preventable..but will going to live on high mountain be the solution? or flying in an airplane or just riding the killer tide with a boat be the answer.

2007-02-11 04:06:13 · 17 answers · asked by kool kat 2 in Other - Science

Why does the cation of a salt affect the color of the flame produced when put under a Bunson Burner?

I am writing a lab report over this question. I have already conducted the experiment, so I already know that the cation is responsible for the color of the flame, but I cannot explain why. So if you have any clue, I'd like to hear what you have to say!

Thanks

2007-02-11 04:06:13 · 3 answers · asked by petwoip 1 in Chemistry

plz help, and if possible plz include steps.

2007-02-11 04:05:51 · 9 answers · asked by Semona_Pwns_You 1 in Mathematics

2007-02-11 04:04:19 · 4 answers · asked by Anonymous in Mathematics

2007-02-11 04:03:48 · 10 answers · asked by joel hanson 1 in Weather

2007-02-11 04:03:37 · 8 answers · asked by Blue girl 1 in Earth Sciences & Geology

Has Pi the same ratio all around the univers? If not what we will see?

2007-02-11 04:02:54 · 3 answers · asked by Jesús V 3 in Mathematics

2007-02-11 04:02:37 · 6 answers · asked by David M 1 in Weather

2007-02-11 04:02:08 · 6 answers · asked by Nayyar I 1 in Other - Science

2007-02-11 04:00:49 · 1 answers · asked by Said 4 in Medicine

this river has been documented to run up hill and not down at any point with a compass you can check and it does

2007-02-11 04:00:41 · 6 answers · asked by Michelle E 1 in Earth Sciences & Geology

2007-02-11 04:00:28 · 3 answers · asked by ? 2 in Mathematics

I am learning metric to household and such for nursing school. I'm having trouble remembering eqivilents for gtt/drams/oz/ml/tsp/T and doing to conversions.

2007-02-11 03:58:15 · 5 answers · asked by Anonymous in Medicine

The weather here in southern New England (USA) is cold but sunny.

2007-02-11 03:56:54 · 11 answers · asked by astrowulf2002 2 in Weather

The probability that an event will happen and the probability that the even will not heppen-

A.has a sum of 1
B.have a quotient of 1
C.have a product of 1
D.have a difference of 0

2007-02-11 03:56:48 · 7 answers · asked by Roman H 1 in Mathematics

I need this before monday, pleeez help!

2007-02-11 03:56:16 · 16 answers · asked by Anonymous in Physics

2007-02-11 03:54:53 · 7 answers · asked by gopaljee j 1 in Medicine

How did they get to the second set? I can't remember the formula or rule. I am studying for the gmat and this is the only thing I'm hung up on. I graduated from HS over 10 yrs ago and my brain is dusty! Please help!!!! This is really bugging me that I can't remember this.

2007-02-11 03:54:46 · 10 answers · asked by Ooohlala 1 in Mathematics

pls can u help me what are the names of the groupes ?

2007-02-11 03:51:19 · 2 answers · asked by Neacsu v 1 in Chemistry

ok i already know that high pressure air is cold and low pressure air is warm but i need to find out why on weather news they talk abouy a high pressure system coming briging warm air.
wtf plz help me

2007-02-11 03:49:41 · 1 answers · asked by frosty 2 in Weather

2007-02-11 03:47:59 · 3 answers · asked by John B 1 in Chemistry