/sci/ - Science & Math

Anonymous Fri Dec 17 14:45:30 2010 No.2216390 [View]
File: 76 KB, 800x800, 1281841504087.jpg [View same] [iqdb] [saucenao] [google]

An amount of a radioactive isotope is allowed to decay. It has a half-life of 10 years. If the sample is allowed to decay for 30 years, what fraction of the isotope will remain?

>>	Anonymous Sat Jul 10 04:25:55 2010 No.1371034 [View] File: 76 KB, 800x800, 1278291321634.jpg [View same] [iqdb] [saucenao] [google] >>1371012

Anonymous Thu Jun 3 18:58:59 2010 No.1098493 [View]
File: 76 KB, 800x800, guys.jpg [View same] [iqdb] [saucenao] [google]

Well I just drank a snapple and the bottle cap said "quartz crystals vibrate 32768 times a second", nothing new but I began to think. Since I'm a curious fellow I began wondering how humans developed "time".

Like how was the length of a second decided?

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/sci/ - Science & Math

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