- #1

chickenonrice

- 4

- 0

## Homework Statement

A falling stone takes 0.33 s to travel past a window 2.2 m tall.

From what height above the top of the window did the stone fall?

Express your answer using two significant figures.

## Homework Equations

Kinematic Equations ~

X= Vi (time) + .5gt^2

Vf^2 = Vi^2 + 2gx

## The Attempt at a Solution

First I determined what the initial velocity was at the top of the window:

X = Vi (time) + .5gt^2

2.2 = Vi (.33) + .5 (-9.8) (.33)^2

Vi = 8.28 m/s

Then I used this velocity as my final velocity in this equation:[/B]

Vf^2 = Vi^2 + 2gx

8.28^2 = 0^2 + 2 (-9.8)x

x = -3.5meters

When I first inputted 3.5 meters into my online homework, it came out to be incorrect. I randomly decided to add -3.5 meters to 2.2 meters and the answer: 1.3 Meters, came out to be correct.

I don't understand why I am adding -3.5 to 2.2.

Thank you in advance.