First, you will investigate purely vertical motion. The kinematics equation for vertical motion (ignoring air resistance) is given by y(t) = y0 + V0t-(1/2)gt^2 where y0=0 is the initial position (which is 1.2m above the ground due to the wheels of the cannon), v0 is the initial speed, and g is the acceleration due to gravity. Shoot the baseball straight upward (at an angle of 90 degrees) with an initial speed of 20 m/s. How long does it take for the baseball to hit the ground? Express your answer with the appropriate units.