Find Time in Air for Ball Launched Upward with 18 m/s

[iac0b]

A ball is launched directly upward from ground level with an initial speed of 18 m/s. (Air resistance is negligible.)

What equation would I use to find the time the ball was in the air?

 

[berkeman]

A ball is launched directly upward from ground level with an initial speed of 18 m/s. (Air resistance is negligible.)

What equation would I use to find the time the ball was in the air?

Welcome to the PF.

Thread moved to Homework Help / Intro Physics.

You would use the Kinematic Equations of Motion for constant acceleration (since the acceleration due to gravity is constant on the Earth's surface). See half-way down this wikipedia page:

http://en.wikipedia.org/wiki/Kinematic_equations#Equations_of_uniformly_accelerated_motion

.

 

[iac0b]

Thanks :)