Finding height when stone's impact increases internal energy by 2450 J

[MentalScrew]

Homework Statement

Okay, I have a total mass of 0.255 of a stone that strikes the ground. Assuming that the stone is initially at rest when it begins falling, how high must the stone be above the ground for the energy of the stone and ground to increase by 2450 J?

Homework Equations

Okay, so m = .255, g = 9.81 and internal energy = 2450, what I need to know is how to arrange them so that I can find an equation for height...

The Attempt at a Solution

Yeah, I really need to know...

 

[mgb_phys]

To get you started, Kinetic energy = 1/2 m v²

 

[MentalScrew]

Yeah, I'm a total idiot. I know that has at least something to do with the equation, but I'm not completely sure. Anymore information you can give me?

 

[mgb_phys]

When you have found the speed see https://www.physicsforums.com/showthread.php?t=110015 for the distance