Science & Mathematics - 17 October 2007

2007-10-17 10:34:08 · 13 answers · asked by Anonymous in Astronomy & Space

hmm i really dont know how to answer this question.. any ideas??

2007-10-17 10:34:04 · 7 answers · asked by Anonymous in Earth Sciences & Geology

2007-10-17 10:31:17 · 6 answers · asked by *:+:♥PebbleZ♥:+:* 2 in Physics

In my Science class today we did like this thing with alk-seltzer and now we have to write a paragraph about the reason why the smaller peices dissolved quicker than the big piece? i need help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

2007-10-17 10:30:09 · 5 answers · asked by Anonymous in Earth Sciences & Geology

For the following problem, we are asked to find dy/dx, [d^2 * y] / [d * x^2], and to state for which values of t is the curve concave upward.


1. x = t^3 -12t, y = t^2 – 1

(the first equation reads as x equals t cubed minus 12t; the second equation reads as y equals t squared minus 1).

For this problem I got:

2t / [3t^2 – 12] for dy/dx;

[-6t^2 – 24] / [(3t^2 – 12)^3] for [d^2 * y] / [d * x^2];

after setting [d^2 * y] / [d * x^2] equal to 0 I had:

6t^2 + 24 = 0, and thus t^2 = -4;

Assuming I did all of this right so far, does this mean that the function does not concave upward anywhere because the square root of negative 4 is a non-real answer, or does is still concave up somewhere? Please explain which is the case and why, and if I did something wrong earlier in the problem (i.e. an algebraic error somewhere), please explain how to do the problem step-by-step.

2007-10-17 10:29:53 · 1 answers · asked by Ryan_1770 1 in Mathematics

In biology today, our teacher taught us that the lipid bilayer on the cell membrane can get broken up by detergents. So if normal cells get damaged by detergents, why don't skin cells? What is different?

2007-10-17 10:28:39 · 2 answers · asked by Andy 2 in Biology

what was the speed of light given to people that went to school in the 60s? my dad thinks it's 33000 but that has changed a lot since then.

2007-10-17 10:27:34 · 10 answers · asked by Sound of Madness 4 in Astronomy & Space

2007-10-17 10:27:07 · 15 answers · asked by Anonymous in Engineering

2007-10-17 10:27:04 · 4 answers · asked by *:+:♥PebbleZ♥:+:* 2 in Physics

Do farts stink in space?

2007-10-17 10:26:31 · 7 answers · asked by Anonymous in Astronomy & Space

An inventive child named Chris wants to reach an apple in a tree without climbing the tree. Sitting in a chair connected to a rope that passes over a frictionless pulley, Chris pulls on the loose end of the rope with such a force that the spring scale reads 327.5 N. Chris's true weight is 465 N, and the chair weighs 173 N. The acceleration of gravity is g=9.8 m/s^2. Find the magnitude of the acceleration of the system. Answer in units of m/s^2.

Had to miss like 5 of my physics classes, have no idea whats going on or how to do any of the problems on my worksheet, any help would be greatly appreciated. Thanks.

2007-10-17 10:25:24 · 1 answers · asked by PhysicsDumbass 1 in Physics

Please!!!!!!!! I really need help. Its for my lab.

2007-10-17 10:24:57 · 5 answers · asked by wintersnowchristmas 1 in Astronomy & Space

how do i do it???

plzz help mee

tanx

2007-10-17 10:22:28 · 13 answers · asked by -x-lollie-x- 1 in Mathematics

how would Newton and Einstein explain the movement of the solar system around the Sun?

2007-10-17 10:21:55 · 5 answers · asked by Dana D 1 in Astronomy & Space

and is this equation a function...
x^2+5 and if so why??

2007-10-17 10:19:27 · 3 answers · asked by . 4 in Mathematics

2007-10-17 10:15:02 · 7 answers · asked by clamar84@sbcglobal.net 1 in Other - Alternative

Warren is 14 years older than Chuck.
Next year Warren will be 3 times as old as Chuck.
How old is Warren?
I got : Warren=X+14 then i'm stuck...

2007-10-17 10:12:50 · 12 answers · asked by persevere 2 in Mathematics

How scientists interpret astrology, so an astrologer about astronomy, do they contradict? If so, whom will you support? Your reasoning please!

2007-10-17 10:11:34 · 8 answers · asked by ? 2 in Astronomy & Space

A 10.0-g sample of a mixture of CH4 and C2H4 reacts with oxygen at 25.0 degrees C and 1.00 atm to produce CO2(g) and H2O(l). If the reaction produces 519 kJ of heat, what is the mass percentage of CH4 in the mixture?

2007-10-17 10:10:43 · 1 answers · asked by Anonymous in Chemistry

this is 4 homework

2007-10-17 10:10:14 · 1 answers · asked by nancy 2 in Earth Sciences & Geology

What are these fairy and leprechaun hauntings you speak of? A friend of my mothers, who happens to be full blood native american (not sure why I felt the need to add that) saw a tree that was teeming in what she could only describe as leprechauns when she was young. I've always wondered about that.

2007-10-17 10:08:36 · 5 answers · asked by Anonymous in Paranormal Phenomena

Having trouble solving this problem

0.35y+0.65(10-y)=0.45(100) .

2007-10-17 10:08:17 · 11 answers · asked by Catus JAck 1 in Mathematics

2007-10-17 10:06:46 · 6 answers · asked by Anonymous in Astronomy & Space

i didnt take any detox or anything out of the ordinary,weed stays in your system up to 35 days,and my drug test came back negative for marijuana,it was only 5 days since i smoke,can someone tell me why my drug test came back negative when i smoked 5 days before my drug test?

2007-10-17 10:05:29 · 6 answers · asked by spunky 1 in Medicine

2007-10-17 10:02:13 · 5 answers · asked by Ray K 1 in Physics

Question 2:
A lunch tray is being held in one hand, as the drawing illustrates. The mass of the tray itself is 0.260 kg, and its center of gravity is located at its geometrical center. On the tray is a 1.00 kg plate of food and a 0.305 kg cup of coffee. Obtain the force T exerted by the thumb and the force F exerted by the four fingers. Both forces act perpendicular to the tray, which is being held parallel to the ground. The length of the tray is .4m. The cup is .38m from the end. Plate is .24m from end. Fingers are .1m from the end and the thumb is .06m from the end. The force of the thumb is down and the force of the fingers is up

2007-10-17 09:59:48 · 1 answers · asked by chicagolakers 2 in Physics

2007-10-17 09:59:05 · 4 answers · asked by dstephanie50 2 in Other - Science

Two ice skaters, Daniel (mass 69.9 kg) and Rebecca (mass 49.6 kg) are practicing. Daniel stops to tie his shoelace and, while at rest, is struck by Rebecca, who is moving at 13.4 m/s before she collides with him. After the collision, Rebecca has a velocity of magnitude 7.1 m/s at an angle of 52.1° from her initial direction. Both skaters move on the frictionless, horizontal surface of the rink.

(a) What are the magnitude and direction of Daniel's velocity after the collision?

(b) angle° (clockwise from Rebecaa's original direction of motion)

(c) What is the change in total kinetic energy of the two skaters as a result of the collision?

2007-10-17 09:54:33 · 1 answers · asked by HighVoltage 1 in Physics

Google Earth doens't, just old snapshots. Im talking live views of street level activity, is this even possible? Would be so fascinating.

2007-10-17 09:54:27 · 3 answers · asked by Anonymous in Astronomy & Space

tan(theta)-sin(theta)=4/9

solve for theta

I feel like I should know this but am stuck. I even know the answer from Maple, but can't figure out the process.

2007-10-17 09:52:55 · 1 answers · asked by Voodoo6969_98 2 in Mathematics