Science & Mathematics - 18 December 2007

a 75 kg box slides down a 25.0 degree ramp with an acceleration of 3.60 m/s^2. Find ,uk between the box and the ramp. What acceleration would a 175kg box have on this ramp?

2007-12-18 04:21:42 · 3 answers · asked by Anonymous in Physics

I'm confused by the word "complementary", I don't know whether to use thymine for adenine or uracil (think thats the correct u-word spelling). Help greatly appreciated!

2007-12-18 04:20:45 · 6 answers · asked by Anonymous in Biology

2007-12-18 04:20:29 · 5 answers · asked by Tristan E 1 in Chemistry

2007-12-18 04:19:39 · 33 answers · asked by cchs.member 1 in Mathematics

2007-12-18 04:19:35 · 20 answers · asked by jessi 1 in Mathematics

2007-12-18 04:17:29 · 8 answers · asked by jessi 1 in Mathematics

friend or foe?!?

2007-12-18 04:14:04 · 7 answers · asked by TAP 6 in Paranormal Phenomena

A student pulls on a rope attached to a box of books and moves the box down the hall. The studen pulls with a force of 185 N at an angle of 25.0 degrees above the horizontal. The box has a mass of 35.0 kg, and ,uk between the box and the floor is 0.27. Find the acceleration of the box.

2007-12-18 04:10:10 · 5 answers · asked by Anonymous in Physics

2007-12-18 04:06:44 · 14 answers · asked by Anonymous in Mathematics

How do you think that energy was created? I know that most people will say that God or another diety created it, but I want to hear the scientif reasons such as the gravitational energy being a negative charge and cancelling out, etc. Please post your answers!

2007-12-18 04:04:16 · 19 answers · asked by Emily loves Nirvana 2 in Physics

A container contains 2 mol of H2 and 1 mol of O2. Write down the probability that all the H2 is in the leftmost 2/3 of the container and all the O2 is in the rightmost 1/3.

I don't need a numerical answer for this, but I'm having trouble conceptualize a correct expression that will solve this problem.

Thank you!

2007-12-18 04:01:41 · 1 answers · asked by elan_longterm_invest 2 in Chemistry

2007-12-18 03:59:58 · 11 answers · asked by Buzzard 7 in Medicine

I need help finding the solution sets to this equations:

1. [32/(x^2-3x+2)]-3 = (x-3)/(x+1)

2. CubeRoot(3x+1) = x-1

3. [5x/(x^2+2x-8)] => 3
note: => means equal or greater than

4. |4x-3|-3>6
note: |4x-3| means the absolute value of 4x-3


Thats all.....thanks

2007-12-18 03:58:41 · 1 answers · asked by RivalMikhail 1 in Mathematics

i just noticed my face isnt symetrical why? and does this make me ugly?

2007-12-18 03:56:02 · 24 answers · asked by Anonymous in Zoology

2007-12-18 03:54:10 · 11 answers · asked by Anonymous in Astronomy & Space

Suppose f(a, b] --> R is continuous, monotonically decreasing, goes to oo as x --> a+ but its improper Riemann integral exists over (a, b]. Like f(x) = 1/sqrt(x) over (0, 1].

Let S_n be a sequence of Riemann sums taken over [a, b], associated with partitions P_n, in such a way that: (1) The norm of P_n (length of the largest interval) --> 0 and (2) For each interval of P_n, the tag point, at which f is evaluated, is its the interval right end point.

Show that S_n --> Int a^b f(x) dx

Are these conditions too rigid? Can any of them be dropped without compromising the conclusion?

Thank you

2007-12-18 03:53:42 · 3 answers · asked by Laura 1 in Mathematics

I realize this may be a completely stupid question, but I think my husband, who is an engineer, is playing a joke on me. He says that the magnetic field from power lines will prevent a tree from growing into power lines, and that the branches will actually grow around and away from the lines, avoiding them all together. I say this is not true, because I've seen work crews out cutting branches around power lines. Is he playing a joke on me, or is this a true phenomenon, and if so, can you please provide scientific basis for your explanation?

2007-12-18 03:53:01 · 9 answers · asked by inoffensive nickname 6 in Earth Sciences & Geology

The density of toluene (C7H8) is 0.867 g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 17.0 g of thiophene in 250.0 mL of toluene.

(a) Calculate the mole fraction of thiophene in the solution.

(b) Calculate the molality of thiophene in the solution.

(c) Assuming that the volumes of the solute and solvent are additive, what is the molarity of thiophene in the solution?

2007-12-18 03:51:50 · 3 answers · asked by Karma564 2 in Chemistry

(a) 1
(b) π
(c) π²
(d) π³

2007-12-18 03:47:49 · 12 answers · asked by Alexander 6 in Mathematics

If evolution is true, then why aren't there humans in various stages of evolution today? Scientists claim that we evolved from apes, but there are no skeletons of "the missing link". Why aren't there living examples of "Cro-Magnon Man"?

2007-12-18 03:46:27 · 17 answers · asked by LC 5 in Biology

A steel reinforcing rod is 12 ft. long and 1" thick in diameter. If a cubic foot of steel weighs 490 lb., how much does the rod weigh (to the nearest pound)?

Can someone explain how to do this?

2007-12-18 03:46:08 · 5 answers · asked by BradleysStar 2 in Mathematics

A 25 kg chair initally at rest on a horizontal floor requires a 165 N horizontal force to set it in motion. Once the chair is in motion, a 127 N horizontal force keeps it moving at a constant velocity. (a) Find the coefficient of static friction between the chair and the floor. (b) Find the coefficient of kinetic friction between the chair and the floor.

2007-12-18 03:43:13 · 2 answers · asked by Anonymous in Physics

i need to know what is the appearance of a green pepper on the inside for science. thanks

2007-12-18 03:42:48 · 4 answers · asked by Lee 2 in Botany

i have to make a working model on the uses of static electricity. i have successfully able to geerate enough from the van de graff generator i had made. now i have to use that electricity in some working model to show some uses. any ideas?

this is a part of my physics project.

2007-12-18 03:42:48 · 2 answers · asked by Arnab Roy 3 in Physics

I liked this girl since elementary (girl A) but I hadn't seen her in years (we’re 18). Anyways I found out what her email was was last year through someone. Anyways at this time I started to like another girl (girl B) and that really prevented me from really getting close to the girl from elementary. Anyways I’ve more or less closed with girl B for reasons that I cant tell you it’s a very long story that’s over a year old and its only recently that I’ve concentrated a bit more on girl A. The reason I brought up girl B was because you people would ask what happened between last year and now if you liked girl A. anyways girl A broke up with her bf so I figured I’d see her again as friends. The first time was about 2 weeks ago and she didn’t show up (I know the reason). Then to kind off make it up, she invited me to a club with her friends. When I got there, she was already drunk and everything, so I more or less spent my night making sure nothing happened to here (I didn’t bring her home because I didn’t have the means and her friends were going to do that). More or less, I watched her make out with a guy gong up and going up the stairs and back down and the works. I figured it was something that only happened like once or twice. When I spoke to her the day later (we tried getting in touch before that) she said that she doesn’t go out to clubs often but when she does, that happens. Now I’m wondering what I should do. I still like her but what are my options? And I don’t know if she knows that I like her. Also, I'm finished with girl B. I only mentioned it because that was the only thing holding to go after the other one. And that’s not my point. What I meant to say was she gets drunk even time at clubs so if it exactly like this every time now what would happen when we go out?

2007-12-18 03:41:51 · 6 answers · asked by Anonymous in Mathematics

A farmer has data indicating that if he plants 30 orange trees per acre, each tree will yield an average of 360 oranges. For every additional tree planted, 15 fewer oranges will be produced per tree. How many trees per acre should the farmer plant to maximize his total crop? State both.

2007-12-18 03:40:15 · 2 answers · asked by C'est Comme Un Rêve 3 in Mathematics

I need help with my biology powerpoint

2007-12-18 03:36:36 · 7 answers · asked by Anonymous in Biology

2007-12-18 03:29:14 · 7 answers · asked by Anonymous in Zoology

suppose v=[-3,6] and w=[4,5] . Find 2w-4v

2007-12-18 03:27:23 · 2 answers · asked by warsane b 1 in Mathematics

What's the world's fastest speed a human can achieve by RUNNING. if you give me by m/s or mi/hr would be appreciated.

thanks

2007-12-18 03:26:35 · 4 answers · asked by Heavy-Metal123 3 in Physics