Science & Mathematics - 14 January 2007

Why do earwigs have wings if they don't use them? Could they fly in the past and what could have changed that?

2007-01-14 07:35:41 · 2 answers · asked by <3DA<3 1 in Biology

18 US Dollars over 24 Canadian dollars and 27 US dollars over 48 Canadian dollars
or
18 US dollars over 24 Canadian dollars and 54 US dollars over 60 Canadian dollars
or
18 US dollars over 24 Canadian dollars and 45 US dollars over 48 Canadian dollars
or
18 US dollars over 24 Canadian dollars and 27 US dollars over 36 Canadian dollars

2007-01-14 07:35:00 · 2 answers · asked by barbjs45 1 in Mathematics

The ramp (picture link) is 18 meters long and 4.5 meters high.

*picture link: http://img206.imageshack.us/img206/2450/scangd4.jpg

a.What force, parrallel to the ramp (Fa) is required to slide a 25 kg box at constant speed to the top of the ramp if friction is disregarded?
b. What is the ideal Mechanical Advantage of the ramp?
c. What are the real Mechanical Advantage and the efficiency of the ramp if a parrallel force of 75 N is actually required?

Please help me with this problem.
I'm having trouble understanding it.

I asked this question before, but I was unable to get any help.

2007-01-14 07:25:44 · 1 answers · asked by vicky p 1 in Physics

2007-01-14 07:24:07 · 3 answers · asked by Angelita A 1 in Mathematics

Q.Integrate x*e^(-x^2) dx
Can anyone see how to do this?
I can't get the product rule to work because I can't integrate the second bit.
Thanks

2007-01-14 07:23:05 · 3 answers · asked by Philip J 2 in Mathematics

for which possible choices of the sets XandY is this machine a function from X to Y
A) x= set of positive integers, y = set of positive real numbers
B) x=set of integers, y=set of real numbers
C) x=set of positive integers y=set of positive real numbers
D) x=set of positive integers y= set of positive integers

2007-01-14 07:21:41 · 3 answers · asked by pkbrauer 1 in Mathematics

2007-01-14 07:20:12 · 18 answers · asked by gooseberry 1 in Mathematics

2007-01-14 07:19:47 · 5 answers · asked by funnyboy642 1 in Chemistry

It was on my homework.

2007-01-14 07:19:10 · 3 answers · asked by music2ustaff 1 in Mathematics

2007-01-14 07:19:04 · 7 answers · asked by Anonymous in Earth Sciences & Geology

The vehicle has to be made just as a working prototype to run for short distance on a flat surface, which has to powered only by gravity and nothing sort of spring rubber band, string etc

2007-01-14 07:18:38 · 5 answers · asked by KT 2 in Physics

Why is it desirable to express concentration as molality rather than molarity when performing experiments in which the temperature changes?

2007-01-14 07:18:01 · 4 answers · asked by Master 2 in Chemistry

2007-01-14 07:17:35 · 6 answers · asked by music2ustaff 1 in Mathematics

Could someone please tell me what the anti derivative of 5x ^ (-1) is , or give me a hint of some kind?

2007-01-14 07:14:48 · 2 answers · asked by rettix 3 in Mathematics

I know that tornadoes occur every year somewhere in the UK and that they will increase in frquecny with global warming (natural or man-made) however what I'd like to know is whether they are also likely to increase in intensity? Will we also be seeing more T8 tornadoes and perhaps even higher as the climate changes?

2007-01-14 07:13:36 · 2 answers · asked by Pole Kitten 6 in Weather

2007-01-14 07:11:48 · 5 answers · asked by lisa b 1 in Earth Sciences & Geology

is it a good idea to talk precalc over the summer? just wondering if it's really hard or not.

2007-01-14 07:11:06 · 3 answers · asked by i like turtles 3 in Mathematics

If u can answer this question then what are the material 2 use when makeing electricity flow 2 make light?

2007-01-14 07:10:45 · 2 answers · asked by Anonymous in Earth Sciences & Geology

2007-01-14 07:08:42 · 4 answers · asked by Anonymous in Chemistry

2007-01-14 07:07:27 · 24 answers · asked by Anonymous in Geography

...what time is it at the south pole..?

2007-01-14 07:06:29 · 15 answers · asked by dnbgrrly 2 in Earth Sciences & Geology

and you are told that when we divide x + 1 into f(x) then the remainder is 0. Based on this information which of these statements is necessarily true?
a= f(1)=0
b= f(0)=1
c= f(-1)=0
d= f (0)=-1

2007-01-14 07:05:35 · 4 answers · asked by pkbrauer 1 in Mathematics

Can anyone find a map of the Pegnitz River? I don't have an atlas and no where on the internet I can find "Pegnitz River map/route" HELP!!!

2007-01-14 07:05:32 · 2 answers · asked by mymandy789 1 in Geography

the following is the correct sequence of steps?

a) 1) enter the number
2) press the x2 (x-squared) key

b) 1) press the x2 (x-squared) key
2) enter the number
3) press the equals key

c) 1)press the square root (check key)
2)enter the number
3) press the equals key

d) 1) enter the number
2) press the square root (check key)

2007-01-14 07:04:51 · 4 answers · asked by WiLLiAm D 2 in Mathematics

2007-01-14 07:04:04 · 5 answers · asked by rednika2000 1 in Physics

I am wondering if the type of clouds in the sky effects the humidity. For instance, if the clouds are overcast does that mean that the humidity level is rising?

2007-01-14 07:02:50 · 2 answers · asked by Anonymous in Weather

I'm writing my report, for my finals, for earth science..
my topic is fossils.
if you can tell me about fossils.
what they do, how they form... basically anything about them.
then let me know.


thank you.

2007-01-14 07:01:58 · 4 answers · asked by Anonymous in Earth Sciences & Geology

i have science homework but i don't know how you work out the mass number or the number of neutronz an element has...

2007-01-14 07:01:08 · 7 answers · asked by big_yin 3 in Chemistry

2007-01-14 07:01:02 · 9 answers · asked by Anonymous in Astronomy & Space

2007-01-14 06:57:14 · 10 answers · asked by scluby2k 2 in Physics