Roger pushes a box on a 30° incline. If he applies a force of 60 newtons parallel to the incline and displaces the box 10 meters along the incline, how much work will he do on the box?

5.2x10^2 joules
6.0x10^2 joules
-5.2x10^2 joules
-6.0x10^2 joules