# Can anybody solve this simple and interesting mechanics problem ......

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Sexy jontyposted 11 years ago

Problem : A bird falls from a tree of 20m height. It reaches to ground in 2sec. A bear sees it from a distance of 40m and run to catch it, reaches in 4sec. What is the visible color of the bear?

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sannyasinmanposted 11 years agoin reply to this

Red with anger. He was too late and the bird flew away.

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ediggityposted 11 years agoin reply to this

The bear is white, because the acceleration due to gravity is closest to 10 m/s^2 at the North Pole.

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Sexy jontyposted 11 years agoin reply to this

BOOOOOOOOM ........

BANG ON THE TARGET ........

ediggity ......

You are the only person who cracked it ....

Very intelligent I must say .....
Kindly everyone at the forum ....
ediggity is right to the answer and those who not understood it .... can post ..... I will help them to explain ....

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Scott.Lifeposted 11 years agoin reply to this

Except there are no trees at the north pole, or birds for that matter, I'm speaking as someone who studies biology, not physics.

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Sexy jontyposted 11 years agoin reply to this

Very well said Scott .....

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Sexy jontyposted 11 years agoin reply to this
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bobcat_robposted 11 years agoin reply to this

No body saw it, because the bear is the one who who saw the falling  bird. another answer, is if the bear is in north pole, maybe its white. if it is in the jungle, maybe brown

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retellectposted 11 years ago

Brown? I dunno? Can't figure it out! Is there something I'm missing? :s

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jenblacksheepposted 11 years ago

No bear could run that fast!

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Sexy jontyposted 11 years ago

Wow men ....... I thought I would be answered in few minutes with that simple question .....
But it took more than two replies .... and 50 minutes ......

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Sexy jontyposted 11 years ago

Somebody answer it ..... it's now almost two hours for the answer to come .....

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Lee Booleanposted 11 years ago

brown, no trees where the Polar bears are

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Sexy jontyposted 11 years agoin reply to this

Sorry lee boolean ..... it's not the correct answer .......

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Lee Booleanposted 11 years agoin reply to this

still puzzled how the bear could run at 10m/second... maybe he has a Lam-bear-ghini

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Sexy jontyposted 11 years agoin reply to this

Lee Boolean just don't go to the reality part .......
Ok let assume :
A bird falls from a tree of 20m height. It reaches to ground in 2sec. A bear sees it from a distance of 10m and run to catch it, reaches in 4sec. What is the visible color of the bear?

Now it's ok ....

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Lee Booleanposted 11 years agoin reply to this

sorry SexyJ, I am stumped...

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Sexy jontyposted 11 years agoin reply to this

Hey Lee Boolean ...... don't give up ..... answer some part is in the question ..... just read it carefully ...... I have given big hint in my previous post ......

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Lee Booleanposted 11 years agoin reply to this

hmm, was wondering about this mechanical problem on my way home, I must say I am a little disappointed at the answer, maybe its one of those "insider" jokes that only makes sense when you assume a degree in physics. I for one would never have even thought about the speed of the bird falling, but then I did have the same argument as Scott regarding trees on the north pole, but I guess the velocity of the bird is a much clearer give away.

Anyhow... here's a quick riddle for you (not nearly as complicated):... why do polar bears eat seals and fish but never penguins?

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Scott.Lifeposted 11 years agoin reply to this

Because there are no penguins in the North Pole only the southern arctic

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This isn't a mechanics problem-- this, if anything, is a velocity question superimposed by ambiguity.

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Sexy jontyposted 11 years agoin reply to this

Think brother ...... just think .......
This question now I am telling you was asked in IIT exams .....
just think more and reply .......

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Helen Caterposted 11 years ago

A bear does not change color so it would be the same as when it set off. Was it a polar bear, black bear, or brown bear? Did the bird fly away as the bear would have been 2secs too late. Did the bird die? Did the bear eat it? Maybe the polar bear would look a little red around the mouth. I hate these riddles.

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Lee Booleanposted 11 years agoin reply to this

you mean you cant -bear- these riddles?

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Helen Caterposted 11 years agoin reply to this

It's grizzly!!

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Lee Booleanposted 11 years agoin reply to this

polar-izing to say the least...

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flighty02posted 11 years ago

Well now, assuming that the bird was dead before the bear got there (2 seconds too late) the bear wouldn't have a visible color to the bird.

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Sexy jontyposted 11 years ago

sannyasinman :  Well tried men ...... but wrong .......

Helen Cater : Don't know the answer ...... It's fine ...... but don't say it a riddle ..... The topic says "MECHANICS PROBLEM" ......
So there may be a valid answer to it ...... Not a riddle answer .....

flighty02 : A real bad answer to a simple mechanics problem .....

Lee Boolean : I think you have quit it way before ......

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Helen Caterposted 11 years ago

I guess we better all stay away from this thread as we are dumbos.

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Sexy jontyposted 11 years agoin reply to this

Now who says that ........ I am not saying anyone dumb .... but I am just saying your attempt to reason is wrong that's it ....

Helen Cater your hubs and fan club shows that you are far more creative than me ......

This forum is just for the fun .......... So let's enjoy ......

Sorry for previous post ........

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The bear can't run that fast, so it's a moot question.  I think that's the right answer, or the sought-after answer, looking back at the other posts.

It seems silly, though, like one of those papers with 90 instructions listed, and the first instruction is "read all the instructions before you begin", then it goes, take five, add two hundred, next instruction:  divide by five, next instruction:  multiply by seven...until you get to the last instruction, which says, "disregard all the instructions except for #1."

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Sexy jontyposted 11 years agoin reply to this

paradise7 ..... you're mistaken by whole of the problem ...

It's a mechanics question ..... so what's in the question if I say car runs at 200km/sec .....

on earth there is no such car ..... but if I put it in a question .... just by few calculations you would arrive to a answer which is practically not possible .... but on the paper and question it's the right answer .....

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The bear is white.  Is it?

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Sexy jontyposted 11 years agoin reply to this

And the reason .......

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Ah, I got it.

Don't want to spoil the thread for other people.  It only LOOKS white...

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Sexy jontyposted 11 years agoin reply to this

please I said two colors ...... Ok white ...... give the reason ... and spoil the thread .....

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Come on Paradise - spill it

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Sexy jontyposted 11 years agoin reply to this

He don't know the reason .... he's just guessing ....

HINT 2 :  Apply newton's equations of motion ......

And you're to the answer ....

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Helen Caterposted 11 years ago

I'm just going to sit and wait for the answer as I said I am useless at this and no offense taken. I just want to know the answer.

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Sexy jontyposted 11 years agoin reply to this

HINT : There are two answers(colors) ..... One visible color and one actual color  ....

Think .......

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The bear is the same color as the tree trunk and when he saw the bird fall he had to climb down 10m, which took him 4 seconds. However, the bird hadn't hit the ground before the bear started climbing down so the time of the bird falling and the bear climbing down were overlapped.

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Sexy jontyposted 11 years agoin reply to this

Madame X ..... not read the question properly .... Bear is not over the tree .... He is at distance from the tree .....

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The OP states that the bear saw it "from a distance". It didn't say whether that distance was horizontal or vertical.

Ok let assume :
A bird falls from a tree of 20m height. It reaches to ground in 2sec. A bear sees it from a distance of 10m and run to catch it, reaches in 4sec. What is the visible color of the bear?

But I guess I'm still not right . . .

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Sexy jontyposted 11 years agoin reply to this

Madame X ..... It's the horizontal distance .....

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HealthTipposted 11 years ago

"What is the visible color of the bear?"

Could you possibly mean black and white as a bear sees things in black and white ?

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Is the bear "white" becasue he's streaking so fast through the woods to get the bird?

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Sexy jontyposted 11 years agoin reply to this

No ..... Madame X it's mechanics ........

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habeeposted 11 years ago

We give!

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The bear is black and white because it's a Panda Bear hehehe

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The underlying physical premise is faulty, anyway.

At least, I think it is.  I may have the wrong reason.  I want sexy to spill it. That way I won't look like such an idiot.

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There's no crime in looking like an idiot - I do it all the time . . .

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poetlorraineposted 11 years ago

he did not catch it...... it fell to the ground

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Scott.Lifeposted 11 years ago

1035 Hubs in Nine Months, now there's a math problem I can't figure out. WOW, you must live on Hubpages.

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Sexy jontyposted 11 years ago

Wow .... my simple problem is not yet answered ......

It's now 14 hours and 45 replies ago when I asked .....

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Don't be cruel.  Everyone gave up.  Tell.  Please?

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I think he is just messing with everyone. Right now he's probably changing pants because he was laughing so hard.

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I thought I had it once, but then I saw a huge gaping flaw in THAT theory.  Maybe you're right, it's a piece of silliness and sexy is laughing up the sleeve right now.

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Sexy jontyposted 11 years ago

Ok .... For the people who are unable to figure it out ....... here goes my other hint .....

HINT 3 : Use the formula .....

S=ut + 1/2 a(t)2 ......

the 2 in the red states that it is (t) square......

Reading of formula goes like this ....

S is equal to (ut) plus half a*(t) square .....

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Sexy jontyposted 11 years ago

It can also be read as ....

S = ut + 1/2 a* t^2 ......

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Andres Canalesposted 8 years agoin reply to this

The same color the bear always was. Remember, every formula works only within a range, and nothing at 4m/s will change of color, try it.

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I was way out in the hinterland.  I had that thought of acceleration due to gravity but connected it in a different way to the bear.  I still had the answer "white", but not any where near a justifiable reason.

Thanks for spilling the beans.  It was getting to me.

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ediggityposted 11 years agoin reply to this

Well you thought of acceleration due to gravity, that's basically the answer, and you got the right color.  You get full credit from me.  I didn't bother reading through the posts.  I just answered the question, so I will go back and read your answers.  Good Job!

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Sexy jontyposted 11 years agoin reply to this

Eddggity now part for the other color ..... The actual one ....

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ediggityposted 11 years agoin reply to this

I'm color blind.  I only see in black or white.  The visible spectrum of light varies at the Poles, and at the North there is total brightness.  In the summer the bear would be yellowish, because of oxidation, or greenish due to algal growth.  Black is the skin color, and it could reflect white.

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ediggityposted 11 years ago

Thanks, but it only helps if you have/had a physics background.  Otherwise, most people would think about it philosophically, and not no where to start.

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Sexy jontyposted 11 years agoin reply to this

That's right ediggity .....
I have a good physics background ....
But forum answer are just like what you say (philosophical).......

That's it wait for my other question ....

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ediggityposted 11 years agoin reply to this

I love how I just answered a physics problem, and then misspelled the word know.

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Mishaposted 11 years ago

Umm, so the difference between 9.78 m/s2 on equator and 9.82 m/s2 on any pole is enough for that? Frankly does not make much sense to me. This difference is way less than the one between 10.0 and 9.82... If this is really the answer, i would say quite silly quiz...

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ediggityposted 11 years agoin reply to this

It's a generalization, but yes the difference in gravity would affect the maximum velocity enough to make a difference.

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Mishaposted 11 years agoin reply to this

Seriously? Just a hint - for that to make anything close to sense, this bird had to fall from 19.64m. Maximum 19.67m. Now figure out why

Oh, and there are no trees of that height where polar bears live, that's another hint from Scott to question idiocy. If you make a distinction between polar bear and grizzly, you have to take their habitat into account, too.

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ediggityposted 11 years agoin reply to this

Like I said, it's a generalization (not exact), and yes it does make a difference.  Look at how to launch a space shuttle.  I already addressed Scott's post to Flightkeeper, and there was nothing wrong with what he said.  I don't need to "figure it out"  Here's a hint, I already did.

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Mishaposted 11 years agoin reply to this

You obviously never been even close to people who launch shuttles. Educate yourself about the theory of errors, it really can open your eyes.

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ediggityposted 11 years agoin reply to this

Yep, you're right.  I'll try to educate myself more, so one day I can become close to the space shuttle launchers.

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Sexy jontyposted 11 years ago

The other actual color is .... black .....

White is beacause the polar bear fur reflects sunlight .......

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ediggityposted 11 years agoin reply to this

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Sexy jontyposted 11 years agoin reply to this

where that limits tends to ..... is it 0 or infinity or it looks like a shape of earth in your question ......

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ediggityposted 11 years agoin reply to this

It's the earth.

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Sexy jontyposted 11 years agoin reply to this

Wrong question ...... where is the function ......

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ediggityposted 11 years agoin reply to this

The function is everything and Alpha and Omega is what goes into it.

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Sexy jontyposted 11 years agoin reply to this

kindly ... check it again it's again wrong queation .....

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ediggityposted 11 years agoin reply to this

Just write out what it says, and you have the answer.

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Sexy jontyposted 11 years agoin reply to this

Hey .... I thought you want the proof .... L.H.S = R.H.S ....
Is this a question or it's the fact you are telling to the world .....

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ediggityposted 11 years agoin reply to this

No proof, I just wanted you to answer.  The proof is right there in front of you.

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Sexy jontyposted 11 years agoin reply to this

your question says if limit x--> 0 so f(x) would be infinity .... That's wrong question ....

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ediggityposted 11 years agoin reply to this

It says as Alpha and Omega approach the world.

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Sexy jontyposted 11 years agoin reply to this

I got it .... are you talking about the alpha from universe that approaches to earth would destroy it .....

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ediggityposted 11 years agoin reply to this

You're thinking in the right direction.  You forgot the Omega.  The Alpha and the Omega.

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Flightkeeperposted 11 years ago

I'm sorry this was stupid.  I thought it was a riddle and not a physics question.

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ediggityposted 11 years agoin reply to this

What a debbie downer.  What was your riddle answer?  Like Scott said there are no trees in the North Pole, so you might be right also if you justify.

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Flightkeeperposted 11 years agoin reply to this

Yes, I'm a debbie downer. I still think it was dumb.

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ediggityposted 11 years agoin reply to this

You still didn't give your riddle answer.  What were you thinking it was?

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Flightkeeperposted 11 years ago

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ediggityposted 11 years agoin reply to this

Jointy's rules not mine.

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Sexy jontyposted 11 years ago

Is that something to deal with christianity or greek alphabet .....

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ediggityposted 11 years agoin reply to this

Christianity.

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Sexy jontyposted 11 years agoin reply to this

Does it relates to Jesus saying I am the alpha and Omega ....

or it relates to tipler's theory .....
or it relates to omega point .......

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Sexy jontyposted 11 years agoin reply to this

Hey ediggity where are you ..... reply .....

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Sexy jontyposted 11 years agoin reply to this

Ediggity when you arrive we would continue .... but for now I am thinking for a new good question ......

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Sexy jontyposted 11 years agoin reply to this

or it relates to collision to two bodies and shape appears to be of infinity symbol ......

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Lee Booleanposted 11 years agoin reply to this

that sounds like something from the kamasutra

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Sexy jontyposted 11 years agoin reply to this

It's collision of two spheres dude not the kamasutra .....

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Lee Booleanposted 11 years agoin reply to this

pity really, sounds like much more fun for two bodies to keep at it for eternity

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ediggityposted 11 years agoin reply to this

Yes, exactly, it relates GOD and to revelations the beginning and the end.

I thought Tipler's theory was Omega Point?

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Sexy jontyposted 11 years agoin reply to this

So ediggity ..... It looks to me the question says when the beginning and end approach to earth ...... Their functionality together would be infinite ........

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ediggityposted 11 years agoin reply to this

Yes exactly.  Good Job!

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Sufidreamerposted 11 years ago

lol - Not going to give the answer and spoil your fun, Lee - it might trap a few people, though

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Sufidreamerposted 11 years ago

You spoilsport, Scott!

I reckon that you should provide us with a riddle, now

Preferably one that is not a physics 'in' joke.

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Lee Booleanposted 11 years agoin reply to this

I agree with Sufidreamer, Scott you're it!

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bobcat_robposted 11 years ago

Ok here is a simple riddle. If  very big basket is being filled up with candies and it takes 1 hour to fill it up. Rate of filling is that, the number of candies inside the basket doubles every minute. how long it will take for the basket to be quarter full?

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Lee Booleanposted 11 years agoin reply to this

I think I have this one... 58 minutes since the basket is full in 1 hour, and the quantity is doubled every minute, i.e. 60= full, 59= half full, 58 = quarter full....

did I win anything?

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bobcat_robposted 11 years ago

Ok here is a simple riddle. If  very big basket is being filled up with candies and it takes 1 hour

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R.G. San Ramonposted 11 years ago

Oops. I can't believe I missed this thread. I hope I'm not too late. Just want to share an answer (without the math).

When I looked at the post, the first thing that came to my mind was "green." Yes. Not that I'm green, but that if there was a tree, and a bird fell from a tree (perhaps a young one, trying to fly from its nest), and that a tree with a nest is absurd without its leaves, then the bear, even if painted blue by its owner ('cause a bear wouldn't run that fast without a trainer), will look green if you're looking from above ('cause the bear would have run for you instead if you're on land).

Does this count? Or am I imagining too much? Or assuming too much?

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ediggityposted 11 years agoin reply to this

The answer was focused toward physics and not philosophy, but all answers count.

The bird in the tree falling was used to calculate the gravity of the place where the bear and bird were.  When you calculate the gravity it is closer to 10 m/s^2, which is at the North Pole.  A bear at the North Pole would be white.  The numbers used were nice and easy, so one could do the calculations easy.  The actual gravity at the North Pole is not 10 m/s^2, but closer to that than anywhere else.

y=20m
t=2s

x=40m
t=4s

V^2=Vo^2 + 2(a)(y)

x/t=Vx

y=V-Vo/2 * (t)

V=0 because the bird hit the ground

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R.G. San Ramonposted 11 years agoin reply to this

Yeah I know, eddigity; I read through the entire thread. Just wanted to share a different perspective. But thanks for taking the time to respond.

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Mikewerkposted 11 years ago

My guess is the bear would appear as a gray streak because the eye can only receive so much visual information at one time. Brown being a blended color and not a primary color might also attribute to the color distortion. If the bear were Red, Blue or Yellow, the eye would have less information to process and therefore see it in its natural color.

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zampanoposted 11 years ago

sexy joint :
does it bear a big pair of tits ?

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Nick Bposted 11 years ago

Who cares?

The fact that the bear is running at 36 kph would mean that I for one would have got the hell out of there pronto.

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garrukastrukposted 11 years ago

i cant remember pass word.
anyway, if the bird can fall vertically twice as fast as the bear can run horozontally that could be called in a mecanical term as a two to one compound ratio. but that is only part of that type of posible mech. nominclacture. somewhere it must be associated with an accual "visible" color posibly ryming with a mech. formula? am i warm\cold?

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darktriangleposted 11 years ago

From who's viewpoint????????????????????????????????????

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Will Bensonposted 11 years ago

If the bird falls to the ground in 2 seconds, it couldn't have been at the top of the tree - so it didn't fall very far.

Polar bears see well but don't live where trees do. Not white.

Brown bears live where trees are but are considered to have the poorest bear eyesight (although this is challenged by some). Not brown.

Black bears see well enough to spot a falling bird at 40m and live where there are trees.

My ans is "Black."

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zampanoposted 8 years ago

The bird fell from 19.6m high.
The colour is Black.
And it was not a bear.
It was Usain Bolt. haha !

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