Suppose Charlie OBrian of the Braves hits a baseball straigh

Suppose Charlie O\'Brian of the Braves hits a baseball straight upward at 150ft/sec from a height of 5 ft. How long does it take for the ball to return to earth?

Solution

Using the equation: h = -16t^2 + 150t + 5, where
h = height after t seconds
-16t^2 = downward pull of gravity
150t = upward rate of the ball
5 = initial height (where ball was hit)
:
-16t^2 + 150t + 5 = 0
:
Using the quadratic formula: a=-16, b=150; c=5
the positive solution: t ~ 9.41 seconds