A locomtive is pushing a 2.20+E5 N boxcar - Physics help

I am doing Abeka Physics and just got stuck on Chapter 11. This is one of the problems in that chapter.A locomtive is pushing a 2.20+E5 N boxcar exactly 3.20 km up a 30.0 degree slope at a constant speed of 15.6 m/s. How much work is the locomotive doing? Ignore friction.
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