# calculus

an object is dropped from a tower. the distance in t seconds is given by d(t)=4.9t^2
if the height of the tower is 146.9m , how fast is an object moving when it hits the ground??

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1. V=dh/dt= d(4.9t^2/dt=9.8t

but t can be found from 146.9=4.9t^2

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2. Your equation should have been

dt) = - 4.9t^2

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