Afemale orb spider has a mass of 0.55 g . she is suspended from a tree branch by a 1.2 m length of 0.0020-mm-diameter silk. spider silk has a density of 1300 kg/m3.
if you tap the branch and send a vibration down the thread, how long does it take to reach the spider?

Scientist have use computer models to create a series of maps that show how susceptible coastal cities in island countries are to the sea rising at different levels. the map shows that a 1 meter rise would swap cities all along the us eastern seaboard. a 6-meter sea level rise with sub merge a large part of florida. thermal expansion has already raise the oceans 10 to 20 centimeters the most likely cause, directly and indirectly, for such a rise in sea level is