question and answer thread.
Lets play questions and answers... Some one asks a question and whoever sais the right answer first gets to ask the next question (oh and marks a point... we could make it as a contest)
Wanna try? It'll be cool (I think) ;) :rolleyes: :D :)
So... first question:
Two camels are galloping towards each other through a desert with a speed of 60 km/h (fast isn't it). A fly keeps flying from the nose of one camel to the nose of the other with a speed of 200 km/h (even faster). Two hours after starting the gallop the camels meet. Each one has passed 120 km. But what distance has the fly flown?
trick question
Re: question and answer thread.
If we take our reference coordinate system of observer1 in rest (relative to the earth) at the location of the nose of the one camel the fly is flying away from, he will notice that the nose of the other camel is appoaching the nose of the first camel with a speed of 120 km/h. If the fly approaches the nose of the other camel at 200 km/h, this means the fly is flying at 80 km/h (200-120) km/h for observer2 in a reference coordinate system attached to the first camel (so e.g. an observer on the camel) and thus at 60 km/h + 80 km/h = 140 km/h for observer1. So after two hours observer1 will notice the fly has traveled 280 km with respect to the fly's original position, observer2 will notice the fly has flown 2h*80 km/h = 160 km with respect to the fly's original position while observer3, which we assume in a reference coordinate system on the other camel, will notice the fly has traveled 2*200 km/h = 400 km with respect to the fly's original position.
But your data are actually incomplete. It is not clear what speed the fly is flying in who's coordinate system and whether the distance is with respect to the fly's original position, or observer 1,2 or 3's start or end position. So I made a wild guess and assumed some of these data. :rolleyes:
Re: Re: question and answer thread.
Quote:
Originally posted by Simon666
But your data are actually incomplete. It is not clear what speed the fly is flying in who's coordinate system and whether the distance is with respect to the fly's original position, or observer 1,2 or 3's start or end position. So I made a wild guess and assumed some of these data. :rolleyes:
... and the distance between 2 noses is not provided.
Re: Re: question and answer thread.
400 is the correct answer.
Quote:
Originally posted by Simon666
your data are actually incomplete. It is not clear what speed the fly is flying in who's coordinate system and whether the distance is with respect to the fly's original position, or observer 1,2 or 3's start or end position.
The problem clearly states the movement of each animal! Read more carefully. I think you're just saying that because you wanted an excuse for getting it wrong at first :p. Besides, the coordinate systems were not in the problem, they were created by you.
Quote:
Originally posted by aio
... and the distance between 2 noses is not provided.
Not necessary.
Re: Re: question and answer thread.
Quote:
Originally posted by Simon666
If we take our reference coordinate system of observer1 in rest (relative to the earth) at the location of the nose of the one camel the fly is flying away from, he will notice that the nose of the other camel is appoaching the nose of the first camel with a speed of 120 km/h. If the fly approaches the nose of the other camel at 200 km/h, this means the fly is flying at 80 km/h (200-120) km/h for observer2 in a reference coordinate system attached to the first camel (so e.g. an observer on the camel) and thus at 60 km/h + 80 km/h = 140 km/h for observer1. So after two hours observer1 will notice the fly has traveled 280 km with respect to the fly's original position, observer2 will notice the fly has flown 2h*80 km/h = 160 km with respect to the fly's original position while observer3, which we assume in a reference coordinate system on the other camel, will notice the fly has traveled 2*200 km/h = 400 km with respect to the fly's original position.
But your data are actually incomplete. It is not clear what speed the fly is flying in who's coordinate system and whether the distance is with respect to the fly's original position, or observer 1,2 or 3's start or end position. So I made a wild guess and assumed some of these data. :rolleyes:
I'll take this for correct. :D So you get to ask the new question Simon.
Re: Re: Re: question and answer thread.
Quote:
Originally posted by aio
... and the distance between 2 noses is not provided.
Yes it is:
Quote:
Originally posted by SeventhStar
Two camels are galloping towards each other through a desert with a speed of 60 km/h. Two hours after starting the gallop the camels meet.
That is already enough info.
Quote:
Originally posted by SeventhStar
Each one has passed 120 km.
Confirms data. I'll try to think of a good question to post.
And about my post, I formulated it rather quickly and thus not entirely clear or correct. I should have stated "with respect to the fly's original position in the reference coordinate system of observerX" to make it more clear.