What is the final velocity of a dropped package in free fall?

[jpd5184]

Homework Statement

a hot air balloon is ascending at the rate of 10 m/s and is 61 m above the ground when a package is dropped over the side.

with what speed does it hit the ground

Homework Equations

y(final) - y(initial)= vt + .5at^2
v(final)=v(initial) + at

a= -g = 9.8 m/s
v(initial)= 10m/s
y(initial)=61m
y(final)=0m
v(final)=?
t=4.69 s and -2.65

The Attempt at a Solution

what i did was used the equation V(final)=V(inital) + at and plugged in the numbers

V(final)= 10m + 9.8(4.69) = 55.962

not sure what i am doing wrong. am i using the wrong initial velocity?

 

[ehild]

The balloon is ascending so the initial velocity is upward, the final is downward. g is downward, the initial velocity and the acceleration have opposite signs.ehild

 

[mplayer]

I think the sign of your initial velocity is wrong.