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## Homework Statement

A guy on the top of a 25m building throws a ball upwards with a initial vel of 12 m/s. A guy 31 m from the building catches it at the bottom of the building. What must be the average speed of the guy to catch it at the bottom.

## Homework Equations

Using the Kinematics equations, and using acceleration = -9.80 m/s^2 and v= 0, I find the time up to be 1.22s. Then I find the distance up as 7.35m. Then I find the time it takes to fall down by adding 7.35 to 25 m, using initial velo as 0, and acceleration. But I get a negative on one side in this equation, x = vint(t) + (1/2)(a)(t^2). What am i doing wrong?

I know once I get this time I add it to 1.22s. Then I believe I use v=d/t and plug in 31m for distance and the total time.