Science & Mathematics - 16 January 2007

and how to slove sinxsq(pi/8)

2007-01-16 19:17:48 · 3 answers · asked by wo 2 in Mathematics

Suppose you have displayed a sine wave with V = Vosin(wt) on the screen, where Vo=5V and 2=5kHz. Assume further that the signal triggers the scope when V=2.5V and wt=30.

EXAMPLE:
Suppose you double the amplitude of the wave without changing any oscilloscope settings. What are V and wt now when the scope is triggered? [Answer: the level hasn't changed so the scope still triggers when V=2.5V. V=2.5=10sin(wt); wt=sin^–1(2.5/10)=14.4775121851511.]

QUESTION:
Assume that you reduce Vo back to 5 V and switch the trigger slope polarity from '+' to '-' without changing the trigger level dial. What are V and wt when the scope is triggered now?

2007-01-16 19:14:14 · 3 answers · asked by Anonymous in Physics

2007-01-16 19:09:54 · 9 answers · asked by jutsu 1 in Mathematics

2007-01-16 19:09:29 · 8 answers · asked by ramaprakash r 1 in Earth Sciences & Geology

2007-01-16 19:08:57 · 2 answers · asked by Anonymous in Botany

Well I am just beginning to learn about evolution. It fascinates me and I have a few questions. Why have we begun to loose hair? And turn in to the current species we are now. How would more hair hinder us? Maybe mating choices were influenced by how much or how little an animal had? And were the dinosaurs are ancestors. Or are they ancestors of our ancestor. For some reason I just realized that is probably true haha. I just proposed the question to myself a few minutes ago without thinking.

And my last question is. What are some books I should read to study evolution. I am a fan of Richard Dawkins would you recommend his older books. Are they more about evolution then atheism I am not really sure. Thanks for taking time to answer.

2007-01-16 19:07:43 · 17 answers · asked by Beaverscanttalk 4 in Biology

2007-01-16 19:07:15 · 9 answers · asked by SM ORANGE MT 1 in Geography

I was listening to some music and I yawned, and it sounded like the pitch dropped a couple of steps, I thought somethin was wrong with my speakers but after I was done yawning, it sounded normal again.

Stwange.

2007-01-16 19:06:43 · 5 answers · asked by Anonymous in Biology

2007-01-16 19:06:33 · 4 answers · asked by jutsu 1 in Mathematics

2007-01-16 19:04:56 · 6 answers · asked by icon 1 in Biology

2007-01-16 19:04:21 · 5 answers · asked by bowen91 1 in Earth Sciences & Geology

Why might strobe frequencies lower than the frequency of vibration of the rope appear to "freeze" it? What frequencies would do this?

2007-01-16 19:02:59 · 4 answers · asked by summer6_85 1 in Physics

2007-01-16 19:01:09 · 3 answers · asked by bambam4289 1 in Chemistry

i forget how to convert weight into mass. how much mass does a 100lb block of ice have? is it 100/9.8 or something? anyway, say it has mass m. how do you multiply this number by the speed of light? and then to multiply it again by the speed of light. what number do you use for the speed of light? does it matter if you use metric or not? the speed of light is a distance over time number. what is the distance measured in, and what unit of time makes his equation true?

2007-01-16 19:00:42 · 4 answers · asked by JizZ E. Jizzy 2 in Physics

2007-01-16 18:58:30 · 5 answers · asked by b_77p 1 in Earth Sciences & Geology

The GRID REF IS OS MAP 177 Grid Ref 386 780 and location is near Greenwich University.

2007-01-16 18:54:42 · 1 answers · asked by neil h 1 in Mathematics

A closed recycling bin is in the shape of a rectangular box. Find the height of the bin if its length is 18 feet, its width is 8 feet, and its surface area is 496 square feet.

2007-01-16 18:42:33 · 6 answers · asked by salharbi444 1 in Mathematics

2007-01-16 18:41:02 · 6 answers · asked by Anonymous in Earth Sciences & Geology

aka..The Devil's Triangle.. do have any clue wat goes on??..vanishing... Alien abuctions... unknown electromagnetic forces.. 10 foot Waves.... or just pure crap..??...

2007-01-16 18:38:44 · 9 answers · asked by Redweedplace ® 3 in Zoology

2007-01-16 18:37:00 · 8 answers · asked by Anonymous in Astronomy & Space

(physics)

2007-01-16 18:36:53 · 5 answers · asked by Anonymous in Physics

2007-01-16 18:36:42 · 4 answers · asked by icon 1 in Biology

2007-01-16 18:35:42 · 1 answers · asked by phoebe e 1 in Biology

2007-01-16 18:35:11 · 3 answers · asked by Anonymous in Physics

2007-01-16 18:31:35 · 5 answers · asked by Muhammad wasim Jafri 1 in Astronomy & Space

Hey Northeasterners/New Englanders - Don't you miss the snow?

I miss the snow. Where is it? Why aren't we getting any? It is screwing me up, I need the snow. It's been a strange winter around here, Boston only got 0.6" so far!

2007-01-16 18:25:05 · 14 answers · asked by Anonymous in Weather

I wonder if when "catch and release" fisherman bring a fish up to unhook him and take his photo, is the fish struggling to "breathe" the whole time, like we would be if you held us under water?

2007-01-16 18:25:04 · 5 answers · asked by Anonymous in Zoology

If 3 men & 5 women do a work in 8 days & 2men & 7 children do the same work in 12 days .How many women can do as much work in a day as 21 children?

2007-01-16 18:24:20 · 3 answers · asked by abc 1 in Mathematics

I've heard it has to do with blood type or the amout of VitB in the blood? Is this true?

Thanks guys :)

2007-01-16 18:21:57 · 14 answers · asked by Candice 3 in Zoology

2007-01-16 18:20:40 · 6 answers · asked by Sunita K 1 in Zoology