A ball is dropped from the top of a building. The height, , of the ball above the ground (in feet) is given as a function of time, , (in seconds) by

y = 1640 - 16t^2
y'= -32t
When does the ball hit the ground, and how fast is it going at that time? Give your answer in feet per second and in miles per hour (1 ft/sec = 15/22 mph).

v(t) = ______ mph
v(t) = ________ ft per second

2 answers

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The trough is in the shape of a triangular prism. It is 5 ft long and its vertical cross sections are isosceles triangles with base 2ft and height 3ft. Water is being siphoned out of the trough at the rate of 2 cubic feet per minute. At any... time t, let h be the depth and V be the volumeof water in the trough.