Acceleration in free fall: find final velocity and height

[Firebird]

Homework Statement

A student drops a ball from the top of a tall building; it takes 2.5 s for the ball to reach the ground.

A.What was the ball’s speed just before hitting the ground?
B.What is the height of the building?

Homework Equations

v=V(not) + at

x=V(not)t + 1/2at(Squared)

V(Squared) =V(not) + 2ax

The Attempt at a Solution

I wrote the following

V(not) = ?
a= 9.80 (Because it is a free fall question?)
t= 2.5
v= ?
x= ?

I think I am missing a variable but I do not know which one.

thanks


EDIT: Will I have to do A2+B2=C2?

If so what will be the legs and what will be the hyp?

 

[Jebus_Chris]

x=V(not)t + 1/2at(Squared)

There is only one unknown in this equation.

and this v=V(not) + at

 

[Firebird]

x=V(not)t + 1/2at(Squared)

There is only one unknown in this equation.

and this v=V(not) + at

How do I figure out the other varibles
I have a and t only how do I figure out the 3rd one?

 

[Jebus_Chris]

Vo or V(not) is your initial velocity. In the problem it says that the student drops the ball, what does that mean according to the initial velocity?

 

[Firebird]

I got it
I got it
I got it
I got it
I got it



Yeah!

Thanks for your help man!