A ball thrown straight upward returns to its original level in 2.5 seconds. A second ball is thrown at an angle of 40 degrees above the horizontal. What is the initial speed ball if it also returns to its original level in 2.5 seconds?

The velocity is  

Explanation:

From the question we are told that

  The time taken by the ball is  t =  2.5 seconds

  The angle made with the horizontal is

Generally the vertical component of the initial velocity is mathematically represented as

Generally at maximum height of the ball the velocity is  v  =  0 m/s and  the time take to reach this maximum height is

    =>          [This because t is duration for the to a fro travel of the ball]

Generally from kinematic equation

Here   given that the direction is against gravity

=>    

=>      

=>      

365.25 earth days are in the year of a light year