Delbert stands at the top of a 300-foot cliff and throws his Algebra book upward, releasing the book 4 feet above the cliff top with a speed of 20 feet per second. Recall that 2 00 ( ) 16s f tt vt s= =− + + gives the vertical position s (in feet) of an object t seconds after it is launched with an initial velocity of 0 v feet per second from an initial vertical position 0 s feet presuming that once launched the object’s motion is affected only by gravity.