Yeah, Six Flags, it wasn't as fun as I expected... Bobbejaanland is better.

It doesn't depend on speed, either way you will fall, if you don't apply a reactional force to the ground. But which direction?!

Whoops, my bad. I had seen a slightly different question a few days ago and assumed you were going at it the same way that we had approached that one.

Here's a good one I heard today.

How many times do I whistle, at which time intervals? Does echo reflection count? And how good is the dog's hearing?

Dog can hear infinitely far, you can whistle as fast as you can in real life, and sound propagates infinitely far.

Just imagine as though you're on an infinite plane with nothing else there other than the dog and you.

I suppose it's about 8 times (edit: more like 7 times - depends on how you count ;P *valid excuse* ) the dog will hear you -

Since it doubles its speed every time, you'll have to count 2^x - and I tried it out...

It reaches sonic speed (which is 343 m/s under normal conditions) at about 2^8.45 (349.706)

That's my guess here... =(

Nope, neither guess is correct.

My guess would be 15
8 times till he's faster than the speed of sound at which time he'll overtake the sound waves of your previous whistles.

I'll assume he'll accelerate the same instance he hears the 8th whistle so he won't hear it twice.
Otherwise: 16

Yeah, 15 is the answer. Everyone I've told that one to had that, "Man, that's a great question" reaction upon hearing the answer. I liked it because it had a good trick.

Hmm, intruiging.

When you use Doppler for a moving observer and standing source. You would see that the frequency will change.

This is the formular for an observer going away from the standing source:

f'=f(c-v)/c
c=sound velocity of source
v=velocity of observer moving away from source

Now for the dog problem we have something analogical:

f'=f(v-c)/v (not entirely sure)

v=velocity of the dog
c=velocity of the whistling sound

f'=1000(350-343)/350=20 Hz (approximately, assuming ideal temperature, pressure)

Too bad... the dog can hear this sound. So yeah 15 times. Unless the whistle is of a lower frequency, like the lower sol on a piano. ~400 Hz?

Yeah - that's a nice trick; Too bad I haven't thought about it that way!

... I need to learn thinking twice ... the right way.

Try with this one, less physics more logical thinking.

You have two strings whose only known property is that when you light one end of string it takes exactly 5 minutes or 10 minutes to burn. The rate at which the strings will burn is completely random and each string is different. How to measure with them 7,5 minutes ?

Hmmm, interesting question.

I'd try to light both strings at the same time.
When the 5 minute string is burnt up, light the other string also at the other end. When that string is wasted, it should be exactly 7.5 minutes?

Yes! The main idea was to light the string on both ends. Notice that it's even easier to burn the first one (lighting on both ends) which is 2,5mins, and then the second one on both ends, which gives 5 minutes, and a total of 7,5 minutes.

Next one:

Find the next object in the following sequence

o, t, t, f, f, s, s, e, n, t, ...

Good luck=D

No!!! I got those tests on my assessment, and I'm still having nightmares about them...



Another one they used was this:

d, o, m, i, s, o,...

I mean, that's just lame... people who don't play music can't possibly know this answer. I hate those consultants who make these tests.

Does o-f-f-s-e-t have anything to do with the answer?

No, 'offset' has nothing to do with it. The answer is incredibly simple, but requires an idea.

btw I ensure you that the answer doesn't require any major knowledge.

e

That I got that as soon as I looked at it possibly says something about how my brain works.

Excellent. Next one:

A man entered a pub. He sat at the bar and started a talk with the bartender. After a few minutes bartender said he had three sons. "How old are they?" asked the man at the bar. "Product of their ages is 72." replied bartender. The man started thinking. "I need more information" he said. "The total of their ages equals the number on the building which is opposite to my bar." said bartender. The man left, saw the number on the building and came back to the bar. "I still need more information" he said to the bartender. "The youngest one LOVES ice cream" said bartender. "Now I know the answer" said the man and smiled.

Yes.. what is the answer?

6, 6, and 2 yo?

Can you explain how you get to the answer, either Shin or Lambert? You just moved right on to the next question without any explanation. Some of us aren't geniuses. :(

Nice=) I have another one:

Fish breeder Peter bought three ponds: one with silver carps, one with rudds and wone with both of them silver carps and rudds. Th previous owner put wrong all the signs (saying which spieces are in a corresponding pond). Now Peter would like to put them back in a correct order, but he don't want to fish to much fishes. He came up with an idea how to do that fishing only one fish at all. How? =)

neat!




Next one:

Assume you're in front of two doors. One door leads to a treasure and the other one to instant death. The doors are guarded by twin brothers. One of the two brothers always speaks the truth and one of them always lies. Since they're identical twins you don't know which one is honest and which one a liar. Which question will you ask to know which door you should take? (to the treasure of course!)

"Hey, shorty, what door does your brother day is the one leading to death?"

And you walk into the that one.

Additional Spam:

This is a common warmth transfer question:

I'm making some tea and I have to add cold milk and sugar to it. So I boil the water and put it in my cup. But suddenly someone is calling me on the telephone (for approximately 10 minutes) and I don't want my cup of tea to be cold when I come back. What do I do?

1) poor the milk in it now
2) poor the milk in it after 10 minutes

If you know the answer, don't tell it too fast, let other people discuss first.