Some Puzzles

[chemist]

#1) When you drink soda through a straw you of course have to suck the soda into your mouth. Now, let's say the straw you use is 15 cm long from the surface of the soda to your mouth (and the straw is going straight up). Then you change to a straw that is 20 m long, climb up a a big tree while leaving the can of soda on the ground, and start to suck the liquid 20 m straight up through your loooong straw. How much harder do you have to suck( ) in order to get the soda into your mouth when compared to the first example where the straw was 15 cm long?

#2) When you throw a dice the chance is of course 1/6 that you will get a certain number. What is the chance that you will get at least one 6 if you throw the dice six times?

#3) How long does it take for a TV satellite to orbit around the earth? Over which "part" of the earth's surface are these TV satellites orbitting?

Cheers

chemist

[chemist]

Hmm, not much interest in these puzzles (maybe they all suck ). Ok, you don't have to be a rocket scientist to solve these. No advanced mathematical calculations required. In fact, you can solve them by just using a little common sense, and, in the case of puzzle #2, a very basic calculation.

Cheers

chemist

[mr_hippo]

#1) When you drink soda through a straw you of course have to suck the soda into your mouth. Now, let's say the straw you use is 15 cm long from the surface of the soda to your mouth (and the straw is going straight up). Then you change to a straw that is 20 m long, climb up a a big tree while leaving the can of soda on the ground, and start to suck the liquid 20 m straight up through your loooong straw. How much harder do you have to suck( ) in order to get the soda into your mouth when compared to the first example where the straw was 15 cm long?

I doubt if the volume in the can is greater than the diameter of the straw x 20m so you will lose the syphon effect.

#2) When you throw a dice the chance is of course 1/6 that you will get a certain number. What is the chance that you will get at least one 6 if you throw the dice six times?

1 in 6

#3) How long does it take for a TV satellite to orbit around the earth? Over which "part" of the earth's surface are these TV satellites orbitting?

It does not orbit - it is in a geostationary position. The part of the earth's surface depends on the satellite's 'footprint'.

Cheers

chemist

[Crossy]

#1) When you drink soda through a straw you of course have to suck the soda into your mouth. Now, let's say the straw you use is 15 cm long from the surface of the soda to your mouth (and the straw is going straight up). Then you change to a straw that is 20 m long, climb up a a big tree while leaving the can of soda on the ground, and start to suck the liquid 20 m straight up through your loooong straw. How much harder do you have to suck( ) in order to get the soda into your mouth when compared to the first example where the straw was 15 cm long?

Atmospheric pressure is about 10,331mm H₂O, since our straw is 20,000mm long air pressure is not sufficient to allow you to suck ANY soda in to your mouth.

#2) When you throw a dice the chance is of course 1/6 that you will get a certain number. What is the chance that you will get at least one 6 if you throw the dice six times?

Stats and Probability was never my strong point. Here it is easier to find the probability of not getting a six. Each time you roll, the probability of not getting a six is 5/6, thus the probability of not getting a six at all is (5/6)⁶ = 15625/46656 = 0.335 . So the probability of getting at least one six is 1 - 0.335 = 0.665

#3) How long does it take for a TV satellite to orbit around the earth? Over which "part" of the earth's surface are these TV satellites orbitting?

A TV satellite is in geostationary orbit, takes 24 hours to go around (so it remains above the same longitude). The satellites are all in a line (the Clarke Belt) 35,786km directly above the equator. http://www.daviddarling.info/encyclopedia/C/Clarke_Belt.html

Edited January 18, 2008 by Crossy

[Smokin Joe]

#1 The straw thing

It's really the air pressure (14.7 psi) that pushes the liquid up the straw. You create the pressure differential by sucking the air out and lowering the pressure in the straw allowing the air pressure to push it up. Max you could achieve would be to create a vacumn and I don't thing 14.7 psi will push it up 20m.

[Smokin Joe]

dam_n, you just be me to it while I was typing.

[chemist]

#1) When you drink soda through a straw you of course have to suck the soda into your mouth. Now, let's say the straw you use is 15 cm long from the surface of the soda to your mouth (and the straw is going straight up). Then you change to a straw that is 20 m long, climb up a a big tree while leaving the can of soda on the ground, and start to suck the liquid 20 m straight up through your loooong straw. How much harder do you have to suck( ) in order to get the soda into your mouth when compared to the first example where the straw was 15 cm long?

Atmospheric pressure is about 10,331mm H₂O, since our straw is 20,000mm long air pressure is not sufficient to allow you to suck ANY soda in to your mouth.

#2) When you throw a dice the chance is of course 1/6 that you will get a certain number. What is the chance that you will get at least one 6 if you throw the dice six times?

Stats and Probability was never my strong point. Here it is easier to find the probability of not getting a six. Each time you roll, the probability of not getting a six is 5/6, thus the probability of not getting a six at all is (5/6)⁶ = 15625/46656 = 0.335 . So the probability of getting at least one six is 1 - 0.335 = 0.665

#3) How long does it take for a TV satellite to orbit around the earth? Over which "part" of the earth's surface are these TV satellites orbitting?

A TV satellite is in geostationary orbit, takes 24 hours to go around (so it remains above the same longitude). The satellites are all in a line (the Clarke Belt) 35,786km directly above the equator. http://www.daviddarling.info/encyclopedia/C/Clarke_Belt.html

Excellent, Crossy.

Regarding puzzle #1: It surprises many people that it doesn't matter if you use an extremely powerful vacuum pump (or one million such pumps) to do the job. It is theoretically (and practically, of course) impossible to suck up any soda all the way through the long straw in the puzzle if you have normal atmospheric pressure at the "test site".

chemist