How long does a ball stay in the air when hit at 18 m/s?

[ash312]

Homework Statement

A baseball player hits the ball straight up in the air with a velocity of 18.0m/s. As soon as the ball is hit, the runner on third base dashes toward the home plate. The distance between third base and home plate is 27.4m. Where will the runner be with reference to home plate when the ball returns to its initial height?

Homework Equations

I am not sure

The Attempt at a Solution

Dont understand how to start the solution

 

[ideasrule]

How long does it take for the ball to come down? How far does the guy run in this time? (Note that without the speed of the runner, it's impossible to answer this question. The answer will be very different if he's running at the speed of continental drift than if he's running at the speed of light)

 

[ash312]

The guy runs at 7.60 m /s

 

[ideasrule]

OK, so how long does it take for the ball to come down?