Algebra
posted by Sherry .
A ball is thrown upward with an initial velocity of 14 meters per second from a cliff that is high. The height of the ball is given by the quadratic equation where h is in meters and t is the time in seconds since the ball was thrown. Find the time that the ball will be 30 meters from the ground. Round your answer to the nearest tenth of a second.
PS: I know the answer, because it was a test question, but I do not know how to come up with it. Please show me steps, I am going crazy here. Thanks for your time:)

What is the ht. 0f the cliff?