- #1

ThiagoG

- 15

- 0

## Homework Statement

A small rock is thrown vertically upward with a speed of

from the edge of the roof of a 30.0-m-tall building. The

rock doesn’t hit the building on its way back down and lands in the

street below. Air resistance can be neglected. (a) What is the speed

of the rock just before it hits the street? (b) How much time elapses

from when the rock is thrown until it hits the street?

## Homework Equations

0=30+18t-4.9t

^{2}

Vx=30-9.8t

## The Attempt at a Solution

For the time I got 9.8s and for the velocity I got -66.04 m/s. I'm not sure where I went wrong.