- #1

notReallyHere

- 3

- 0

## Homework Statement

A projectile is launched straight upward at +63.0 m/s from a height of 85.0 m, at the edge of a sheer cliff. The projectile falls, just missing the cliff and hitting the ground below.

Maximum height = 202.5m

1) Find the time it takes to hit the ground at the base of the cliff.

2) Find its velocity at impact

## Homework Equations

x

_{f}=x

_{i}+v

_{i}t+1/2at

^{2}

v

_{f}=v

_{i}+at

## The Attempt at a Solution

For #1 I tried this:

x

_{i}=202.5 x

_{f}=0 a=-9.80 v

_{i}=0

0=202.5+0+1/2(-9.8)t

^{2}

-202.5=-4.9t

^{2}

41.327=t

^{2}

t=6.429

But that's not the right answer

For #2 I tried this: (It depends on the answer to #1)

V

_{f}=0+(-9.8)(6.429)

V

_{f}=-63.004

But that's wrong too since #1 is wrong. What did I do wrong in #1?