Where we threw balls up in the air and saw how long they stayed up in the air and we used that to figure out how fast we inicialy threw the ball and how high they went in the air and in the last video we did it with specific numbers and in this video I just want to see if we can derive some interesting formulas so we can do the computations really fast in our brains while we're playing this game on some type of a field and we don't necessarily have, have any, any paper around so lets say that the ball is in the air for delta T delta T is equal to time in the air time in the air then we know that the time up is going to be half that which is the same thing as the time down the time up is going to be equal to delta T we'll do that the same color is going to be equal to the time in the air divided by two so how, What was our initial velocity?