Science & Mathematics - 18 October 2007

A hockey puck moving along the +x axis at 0.6 m/s collides into another puck that is at rest. The pucks have equal mass. The first puck is deflected 34 below the +x axis and moves off at 0.46 m/s. Find the speed and direction of the second puck after the collision. [please use positive for counterclockwise (above the +x axis) and negative for clockwise (below the +x axis)]:

2007-10-18 19:18:32 · 3 answers · asked by Anonymous in Physics

1. In each case, determine whether * is associative, whether * has an identity element and, if the latter is the case, whether each element of S has an inverse (with regards to *), ie whether S is a group:
(a) S={1,-1}, * ordinary multiplication of integers
(b) S= the subset of Q consisting of all positive rationals that have a rational square roots, *=ordinary multiplication of rationals
(c) S=R\{0}, the set of all non-zero reals with a*b=|ab|

2. From examples above that are groups, which are abelian?

3. Consider groups Z(subscript n) with binary operation being addition modulo n. Write down operation tables for
(a) n=4,5
(b) n=6

4.Prove that if G=, then G=

5. Let G be a finite group, and let g,x∈ G
(a) prove that x and g^-1xg have the same order
(b) Let a,b∈G. Prove that ab and ba have the same order

This is exam revision. I really appreciate the help. if possible i need full working out and explinations.

Thanks

Don

2007-10-18 19:15:33 · 1 answers · asked by Anonymous in Mathematics

2007-10-18 19:15:20 · 3 answers · asked by sms_singathiya 1 in Astronomy & Space

Two LORAN stations are placed 150 miles apart along a straight shore and act as the foci of a hyperbola. A ship records a time difference of 0.0005 second between the LORAN signals. Set up a rectangular coordinate system to determine where the ship would reach shore if it were to follow the hyperbola corresponding to this time difference. The speed of radio-signals is 186000 miles per second.
What is the equation of the hyperbola?

SHOW ME HOW TO SET IT UP PLEASE

2007-10-18 19:09:23 · 1 answers · asked by Anonymous in Physics

-I've heard varying myths including an explanation about A/C overload...

-I am aware of a single tribe in the state that observes daylight savings time though-

2007-10-18 19:07:35 · 9 answers · asked by Hello There 2 in Earth Sciences & Geology

2007-10-18 19:04:04 · 4 answers · asked by Anonymous in Engineering

Remember Adam & Eve story.
Adam = Reason
Eve = Emotion
Desire causes Emotion to succumb , followed by Reason.
Buddha also declares desire as the root cause of the evil, rebirths, sorrows & misery. And it is the desire(of pleasure) which prevents man from salvation/nirvana.
Desire occurs in various organs of body, stomach causes hunger & activates desire to eat & causes a person to salivate.
Similarly
sexual organ --- sexual desire
Eyes -- sights, travel
Ears -- music
Nose -- smell of scent
If desire is nothing but cells requirement in organs, then it means that cells functioning needs to be checked up. And in cells , its the nucleus which does everything and in nucleus , it is DNA.
So , is the DNA, the root cause of desire?
And since the DNA is a coiled of structure, is this the serpent , the devil which is mentioned in genesis , the one which caused eve to eat the apple( desire).
I know many would say that DNA is the foundation of life without which no living being can exist.

2007-10-18 19:03:27 · 6 answers · asked by Anonymous in Biology

Would speeding be a good way to lose weight?

2007-10-18 18:55:16 · 3 answers · asked by Anonymous in Physics

my questions are 5question

2007-10-18 18:53:10 · 3 answers · asked by Anonymous in Mathematics

the - is takeaway not minus...

I think the answer is = 12y^2 -8y

but ime not quite sure, please tell me where i went wrong

thankyou maths experts!

2007-10-18 18:50:48 · 3 answers · asked by Anonymous in Mathematics

Two LORAN stations are placed 150 miles apart along a straight shore and act as the foci of a hyperbola. A ship records a time difference of 0.0005 second between the LORAN signals. Set up a rectangular coordinate system to determine where the ship would reach shore if it were to follow the hyperbola corresponding to this time difference. The speed of radio-signals is 186000 miles per second.










What is the equation of the hyperbola?



##6 (20 points). For the hyperbola 4x2 - 25y2=100, answer the following:


(a) What are the coordinates of the left vertex?



What are the coordinates of the right focus?




Write the equations for both asymptotes.

2007-10-18 18:49:21 · 2 answers · asked by Anonymous in Mathematics

2007-10-18 18:40:16 · 3 answers · asked by glamour girl 1 in Mathematics

yellowish 1 cm or less in body size with a white streak down the full length of its back. Spider Id plz

2007-10-18 18:37:18 · 3 answers · asked by zandarnia 1 in Zoology

This is a science project on finding out which color of light will heat up water the fastest. So basically, i will use artificial light to heat the water in a jar. But to measure the temperature, i need a few thermometers. The ones that can go into water. Does anyone have any idea where to buy any?

2007-10-18 18:33:08 · 2 answers · asked by Anonymous in Other - Science

Minimize Q = x2 + 2ysquared subject to x+y = 5. Answer to 2 decimal places.

2007-10-18 18:31:58 · 1 answers · asked by Liz C 1 in Mathematics

2007-10-18 18:30:42 · 8 answers · asked by fuzzy19 3 in Mathematics

2007-10-18 18:20:50 · 4 answers · asked by Sophia 1 in Biology

A 90% confidence interval around the variance was calculated. For n=27, the confidence interval was 35.0-88.4. Give the variance of the sample.

2007-10-18 18:20:32 · 1 answers · asked by scrappy1 1 in Mathematics

2007-10-18 18:19:50 · 3 answers · asked by Sophia 1 in Biology

I need to know what mayfly's eat and if you have a pic of their digestive system it would be great!

2007-10-18 18:18:02 · 2 answers · asked by Anonymous in Biology

Solve using systems of equations using elimination.

2007-10-18 18:17:07 · 12 answers · asked by Anonymous in Mathematics

I have several large, thick lichen growing on my maple trees. I have no idea what kind they are but they're larger than dinner plates and a good 2" or more thick and somewhat cupped in shape. They're just beautiful. I've dried smaller ones, but these are so big. Is there any way to preserve them? Thank You!

2007-10-18 18:13:33 · 3 answers · asked by Starr 2 in Botany

(2x-2) / ( (x-1)(x²+x-12) )

becomes

(2x-2) / (x³-13x-12)

becomes

(2x-2) / ( x(x-1)(x-12)

giving me vertical asymptotes at x= -1 and -12??

2007-10-18 18:10:40 · 2 answers · asked by iSmile 2 in Mathematics

Two cars travel the same distance. The first car travels at a rate of 40 miles per hour and reaches its destination in t hours. The second car travels at a rate of 55 miles per hour and reaches its destination 3 hours earlier than the first car. How long does it take for the first car to reach its destination?

2007-10-18 18:09:36 · 6 answers · asked by Anonymous in Mathematics

Whatever happened to TracyTerry?
I'm sure you all remember her... Silly, pointless questions...
Did she get kicked out?
On a Sabbatical?
Frontal lobotomy?

I know... Wrong forum.
I'm just curious as to what may have happened... I guess I kinda miss those goofy questions...

2007-10-18 18:09:08 · 4 answers · asked by Bobby 6 in Astronomy & Space

The area under the force vs. distance graph is the work done to stretch the spring. How does the work depend on the amount of stretch?

2007-10-18 18:06:42 · 4 answers · asked by Natiphy2007 1 in Physics

I relli need this for my thesis too... I dun relli have time to finde out myself...

2007-10-18 18:06:08 · 1 answers · asked by Roxanne 2 in Geography

2007-10-18 18:04:01 · 21 answers · asked by Anonymous in Astronomy & Space

you have:a+b=90
Prove:
cos(a-b)=2sin(a)*sin(b)

2007-10-18 18:02:27 · 5 answers · asked by Amir B 1 in Mathematics

I am doing a research papaer at the last minute and its very late so my brain isn't working right. There is a tool (and its name is at the tip of my tongue) the electrically measures the mass of an object. Is it an electric scale? Its a tool (kinda like a scale) were you place something on it and it gives you the mass. I know its an electric ____ and I'm going to feel like a complete idiot when I finally find what it is, but oh well. Help? lol

2007-10-18 18:01:34 · 5 answers · asked by Kayt 2 in Physics