SOLUTION: A rock falls off a building, and its position after t seconds of free fall is 269-16t2 feet above the ground. The building is 269 feet tall. a. What is the rock�s velocity at

Question 28346: A rock falls off a building, and its position after t seconds of free fall is 269-16t2 feet above the ground. The building is 269 feet tall.
a. What is the rock�s velocity at t=3 seconds?
b. How long does it take the rock to hit the ground?
Answer by Paul(988) (Show Source): You can put this solution on YOUR website!
Differenitate:

=-32x
Lim(-32x) ---> -32(3)=-96
x->3

a) HENCE, the rock's velocity is -96 at 3 second.

b)

x=4.1

Hence, it takes the rock about 4.1 seconds to hit the ground.
Paul.
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