Kinetic energy of roller coaster at 11 m height

[slcxow]

I was able to solve all my other problems for homework but I'm having problems with this one.
Any help would be appreciated. Thanks


A 1200 kg frictionless roller coaster starts from rest at a height of 19 m. What is its kinetic energy when it goes over a hill that is 11 m high?

 

[oldspice1212]

Hint: Conservation of energy