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21.) explain the process occurring inside the mantle that causes the tectonic plates to move.

22.)describe sea floor spreading using two piece of evidence that prove it is happening.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

What is an aquifer for science class

Asilver dollar is dropped from the top of a building that is 1324 feet tall. use the position function below for free-falling objects. s(t) = −16t2 + v0t + s0 (a) determine the position and velocity functions for the coin. s(t) = v(t) = (b) determine the average velocity on the interval [1, 2]. ft/s (c) find the instantaneous velocities when t = 1 second and t = 2 seconds. v(1) = ft/s v(2) = ft/s (d) find the time required for the coin to reach the ground level. (round your answer to three decimal places.) t = s (e) find the velocity of the coin at impact. (round your answer to three decimal places.) ft/s