Science & Mathematics - 10 November 2007

What is Laser radiation that is given out from pen lasers? and what can it do to you? is it dangerouse?

2007-11-10 03:23:35 · 3 answers · asked by Larry 2 in Physics

2007-11-10 03:08:49 · 17 answers · asked by Anonymous in Astronomy & Space

2007-11-10 03:04:40 · 1 answers · asked by hannah_kf 3 in Chemistry

2007-11-10 03:04:09 · 5 answers · asked by Anonymous in Zoology

Question – 4: A box with an open top is to be constructed from a rectangular piece of cardboard with dimensions 5 in. by 10 in. by cutting out equal squares of side x at each corner and then folding up the sides as in the figure.
(a) Express the volume V of the box as a function of x, then determine the range and the domain of this function.









(b) Express the surface area S of the box as a function of x, then determine the range and the domain of this function.








(c) Find the value of x that gives the largest volume of the box.

2007-11-10 02:58:57 · 2 answers · asked by yamisfy 1 in Mathematics

128/ 2... pretend that both of the numbers have radical sign ..because i can't do it here.... how can i simplify this...

another example.... 5*10... pretend that every number has radical sign... please help me

2007-11-10 02:54:20 · 5 answers · asked by hey 3 in Mathematics

i have a machine that requires 440 3 phase power, i have 220 all over the place. can a 440 primary 220 secondary be used in reverse to step up from 220 to 440? 75 kva transformers are easy to come by, but i dont know if they can be used this way.

2007-11-10 02:44:44 · 9 answers · asked by tulmkr 1 in Engineering

My friend needs to know for her geog cw, help!

2007-11-10 02:42:22 · 1 answers · asked by Who's your Doctor? 6 in Mathematics

2007-11-10 02:42:11 · 1 answers · asked by Anonymous in Geography

2007-11-10 02:41:56 · 8 answers · asked by kami 1 in Astronomy & Space

maths

2007-11-10 02:39:24 · 7 answers · asked by samira 1 in Mathematics

maths

2007-11-10 02:36:25 · 4 answers · asked by samira 1 in Mathematics

u=[5,6,7,8,9,10,11,12,13,14,15,16,17]
y=[0,0.8,1.5,2.1,2.9,3.6,4.3,5.0,5.8,6.5,7.3,8.1,8.8]

Determine the linear equation that best fit the measured data using the least squares method.

2007-11-10 02:33:24 · 1 answers · asked by ozi 1 in Physics

i am 63 yrs old and have found out that i have severe arthritis in both hips and need double hip replacement surgery..i have no insurance and wondered if i could get early medicare?? is this possible ??

2007-11-10 02:26:03 · 4 answers · asked by ? 1 in Medicine

No cheating, OK. How did you remember the answer?

2007-11-10 02:24:27 · 13 answers · asked by Anonymous in Geography

how u simplify radicals... for example...

i dont have the radical symbol on my keyboard so can u simplify 345..... pretend that it has a radical ok.... please help me

2007-11-10 02:24:10 · 6 answers · asked by hey 3 in Mathematics

I have a word problem in algebra that I am just not getting. My instructor worked it out with me but I still dont understand....in WORDS....how the numbers were found. Can someone PLEASE help me?

The length of a rectangular field is 2 yards more than its width. Find the width if the area of the field is 120 yd2.
1. Explain why the answer of a width of –12 yards is unreasonable.
2. Give a reasonable answer in its place.
3. Explain why your answer is more reasonable.

L=W+2
L*W=AREA
(W+2)W=120
W^2+2W-120=0
(W+12)(W-10)=0
W+12=0
W=-12 YDS. NOT A VALID ANSWER.
W-10=0
W=10 YDS. THE VALID ANSWER FOR THE WIDTH
PROOF
L=10+2=12 YDS. FOR THE LENGTH.
PROOF
10*12=120
120=120


I have no clue where these numbers are coming from and my
instructor will not explain.

2007-11-10 02:22:46 · 11 answers · asked by B. C 1 in Mathematics

the northern lights look so amazing in pictures and never cease to amaze me but when is the best time to see them in london, England?

2007-11-10 02:10:46 · 10 answers · asked by Anonymous in Astronomy & Space

Found it in my homework packet. I used calculus, but I feel like using pre-cal this time =D!

So here's the problem:

"In figure above, the circle with center C and radius 5 is tangent to both the x and y axes. Line AB is tangent to the circle at point B. What is the slope of Line AB if point B is at (9, -8)?

The circle is at the 4th quadrant. You might want to draw it to do this.

How would you find the slope without calculus?

You might want the equation of the circle:

(x-5)^2 + (y+5)^2 = 25

Thanks!

2007-11-10 02:09:05 · 9 answers · asked by UnknownD 6 in Mathematics

A uniform steel beam of length L and mass m1 is attached via a hinge to the side of a building. The beam is supported by a steel cable attached to the end of the beam at an angle theta, as shown. Through the hinge, the wall exerts an unknown force, F, on the beam. A workman of mass m2 sits eating lunch a distance d from the building.
http://session.masteringphysics.com/problemAsset/1011053/22/MTS_st_3.jpg

a) Find T, the tension in the cable. Remember to account for all the forces in the problem.

b) Find Fx, the x-component of the force exerted by the wall on the beam ( F), using the axis shown. Remember to pay attention to the direction that the wall exerts the force.

c) Find Fy, the y-component of force that the wall exerts on the beam ( F), using the axis shown. Remember to pay attention to the direction that the wall exerts the force.

2007-11-10 02:06:08 · 2 answers · asked by zoro-kun 2 in Physics

2007-11-10 02:02:16 · 4 answers · asked by Steve G 1 in Earth Sciences & Geology

The will of an eccentric millionaire reads as follows: "I leave 4/17 of my estate to my son. 7/13 of the remainder to my wife, 2/3 of this remainder to my daughter and the remaining $2,000,000 to my dog" What is the total amount of the estate?

2007-11-10 01:56:23 · 15 answers · asked by Anonymous in Mathematics

ok i am doing Cambridge maths and this annoys me i understand when the topic is taught but after i can't apply it in real questions. i kno the answers but i dont know how to get them (like the working ) so plz help me and show all the steps
btw this is differentiation

w=3r^3 -2r^2 +r-3

s=3t^2-4t-2

2007-11-10 01:53:40 · 5 answers · asked by ✔|Taking Suggestions For A Name|✔ 5 in Mathematics

A 20 g rifle bullet traveling 205 m/s buries itself in a 3.0 kg pendulum hanging on a 2.9 m long strng, which makes the pendulum swing upward in an arc.
Determine the vertical and horizontal compnents of the pendulum's dispalcement,
vertical m
horizontal m

2007-11-10 01:47:52 · 1 answers · asked by cindy d 4 in Engineering

2007-11-10 01:47:32 · 10 answers · asked by Anonymous in Mathematics

2007-11-10 01:41:58 · 10 answers · asked by ? 1 in Zoology

3(x-2) – x-3 = 4
2 4

2007-11-10 01:36:56 · 8 answers · asked by Shavtay 1 in Mathematics

with a white mustache and hair and dressed all in white laying on his bed......im sure he was making it up.....when i mentioned to him this morning ....he said thanks mom i forgot about it till now...now im thinking about it again......do you think maybe hes fibbing? If i saw that i would have crapped in my pants.....he dosent seem to be scared today but gets almost a panic look on face when talking about it

2007-11-10 01:36:18 · 18 answers · asked by Anonymous in Parapsychology

monkshood, belladonna, foxglove, or lily of the valley? I'd like to plant flowers like these but not if there is a risk animals might eat them and get sick or worse. No danger of children getting to them, just animals.

2007-11-10 01:31:48 · 5 answers · asked by BlueManticore 6 in Zoology

How does the ozone layer help us?

2007-11-10 01:26:58 · 17 answers · asked by Anonymous in Earth Sciences & Geology