A stone is thrown from the top of a building upward at an angle of 30o of the horizontal with an initial velocity of 20m/s. if the height of the building is 45 m.How long does it take the stone to...

A stone is thrown from the top of a building upward at an angle of 30o of the horizontal with an initial velocity of 20m/s. if the height of the building is 45 m.How long does it take the stone to reach the ground?