SOLUTION: A rock is thrown upward with a velocity of 15 meters per second from the top of a 34 meter high cliff, and it misses the cliff on the way back down. When will the rock be

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Question 1145087: A rock is thrown upward with a velocity of 15
meters per second from the top of a 34
meter high cliff, and it misses the cliff on the way back down. When will the rock be 4
meters from the water, below?
Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.

To answer the question, solve the quadratic equation


    -5t^2 + 15t + 34 = 4.


Simplify 


      t^2 - 3t - 6 = 0


and solve it using the quadratic formula.


Choose a positive root.