I know that there are 6000J of work in this problem because I solved it using Potential Energy. I did (20kg)(30m)(10m/s^2)=6000J

I have a can of toys that weighs 20kg and it is dropped 30m and makes an indent in the sand below .402m. I am supposed to find the force the sand exerts on the can of toys. How?

You can use F = ma and your suvat equations to work out the force that must have decelerated the can of toys in such a distance. Please ask further questions if you don't understand!

But all that's going to be is the mass of the can of toys and the acceleration would be change of velocity over the time interval. Yet I know neither the velocity or the time Also that does not include the dent of .402m the can of toys left in the sand. Still a bit confused. Thanks!

You know the acceleration, and the distance dropped, and the velocity at the beginning of the drop. From these you can work out both the time taken and the final velocity using suvat.

Thank you very much I had not been introduced to suvat and I looked it up on Yahoo. Very, very helpful in solving this problem.