Question

A one-kilogram plate on a shelf has 19.6 J of potential energy. If the plate falls from the shelf, what will its maximum velocity be?

Answer 1

(1/2) m v^2 = 19.6 
.5 * 1 * v^2 = 19.6

Answer 2

There are plenty methos, I´ll do it like this.
We know that:
Epg=mgh
Work for h:
h=(Epg)/mg
h=(19,6J)/1kg*9,8m/s²
h=2m
Now, we know that:
v=√2gh
v=√2*9,8m/s²*2m
v=6,26m/s