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Author Question: A 3.00-m-long ladder, weighing 200 N, rests against a smooth vertical wall with its base on a ... (Read 273 times) |
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
Many of the drugs used by neuroscientists are derived from toxic plants and venomous animals (such as snakes, spiders, snails, and puffer fish).