# Velocity Of The Ice As It Hits The Ground?

1. Jan 21, 2008

The John Hancock Center In Chicago Is The Tallest Building In The United States In Which There Are Residential Apartments. The Hancock Center Is 343m Tall. Suppose A Resident Accidentally Causes A Chunk Of Ice To Fall From The Roof. What Would Be The Velocity Of The Ice As It Hits The Ground? Neglect The Air Resistance

Last edited by a moderator: May 9, 2015
2. Jan 21, 2008

### Integral

Staff Emeritus
Seem pretty stright forward, what is your question?

3. Jan 21, 2008

### rock.freak667

1) What did you try?
2) See above
3) Think energy

4. Jan 21, 2008

Ok I Tried

D=343m
Vi=0
A= -9.8 M/s

Looking For Vf=

Vf^2=0^2+2 X -9.8 X 343

And Then I Solved It From There

5. Jan 21, 2008

### Feldoh

Looks like.

6. Jan 22, 2008

### DavidHarmon

s=343 u=0 a=9.8

v^2=u^2+2as

v^2=2as

v^2=2*343*9.8
v^2=6722.8
v=82 m/s

the mistake you've made is putting gravity as -9.8 when it is actually 9.8 as the object is accelerating towards the earth.