**a ball player catches a ball 3.3 seconds after throwing it vertically upward . With what speed did he throw it upward ?**

**Answer:**

use the formula x = (.5)(a)(t^2) + (Vi)(t)

x should equal 0 because the total displacement is zero, and t is equal to 3.3.

a is equal to 9.8 because of the acceleration of gravity.

0 = (.5)(9.8)(3.3^2) + (Vi)(3.3)

Vi(initial velocity) = 16.17 m/s