# Free fall question?

1. Sep 7, 2008

### hershey1

1. The problem statement, all variables and given/known data

A student at a window on the second floor of a dorm sees his math professor walking on the sidewalk beside the building. He drops a water balloon from 18.0 m above the ground when the prof is 1.00 m from the point directly beneath the window. The professor is 170 cm tall and walks at a rate of 0.450 m/s. How close does the balloon come to hitting the professor?

2. Relevant equations

y=v0t + 1/2gt^2

3. The attempt at a solution

I found the displacement to be 16.3 m from subtracting the distance of the building from the man's height. Using the formula, I calculated the time to be 3.3 seconds. This would say that the prof will not be hit by the water balloon since the prof would have walked only 82 cm by then. My answer was 18 cm but it was wrong.

Last edited: Sep 7, 2008
2. Sep 7, 2008

### Hootenanny

Staff Emeritus
Welcome to PF hershey1,

You may want to recheck your calculation of the flight time.