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Author Question: An ore car of mass 4 000 kg starts from rest and rolls downhill on tracks from a mine. A spring with ... (Read 85 times) |
Every 10 seconds, a person in the United States goes to the emergency room complaining of head pain. About 1.2 million visits are for acute migraine attacks.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
The first successful kidney transplant was performed in 1954 and occurred in Boston. A kidney from an identical twin was transplanted into his dying brother's body and was not rejected because it did not appear foreign to his body.
Warfarin was developed as a consequence of the study of a strange bleeding disorder that suddenly occurred in cattle on the northern prairies of the United States in the early 1900s.
Certain chemicals, after ingestion, can be converted by the body into cyanide. Most of these chemicals have been removed from the market, but some old nail polish remover, solvents, and plastics manufacturing solutions can contain these substances.