Problem with Energy Dissipation

[sojo]

Homework Statement

A 4.70-kg steel ball is dropped from a height of 11.0 m into a box of sand and sinks 0.500 m into the sand before stopping. How much energy is dissipated through the interaction with the sand? Express answer using three significant digits.

Homework Equations

Potential Energy = mhg
Mechanical Energy = (1/2)mv^2

The Attempt at a Solution

I thought that the energy dissipated would be equal to the potential energy at the start of the problem. So I found the initial potential energy with the equation mgh = (4.7)(11)(9.8) = 507 However, I submitted this answer and the program said it was incorrect.

 

[TSny]

Hello. Welcome to PF!

What is the total distance the ball travels vertically?

 

[sojo]

I guess it falls 11.5 m including the distance in the sand. Do I include the distance in the sand?

 

[TSny]

Is there any change in gravitational potential energy when the ball moves 0.5 m downward in the sand?

 

[sojo]

Yeah there is. That makes a lot of sense. Thanks for your help!

 

[TSny]

OK. Hope it works out now.