A box of weight w=2.0N accelerates down a rough plane that is inclined at an angle ϕ=30∘ above the horizontal, as shown (Figure 6) . The normal force acting on the box has a magnitude n=1.7N, the coefficient of kinetic friction between the box and the plane is μk=0.30, and the displacement d⃗ of the box is 1.8 m down the inclined plane.

I got Part A, need help with B and C

What is the work Ww done on the box by the weight of the box?
Express your answers in joules to two significant figures.

W=1.8J

B)What is the work Wn done on the box by the normal force?

Question

A box of weight w=2.0N accelerates down a rough plane that is inclined at an angle ϕ=30∘ above the horizontal, as shown (Figure 6) . The normal force acting on the box has a magnitude n=1.7N, the coefficient of kinetic friction between the box and the plane is μk=0.30, and the displacement d⃗ of the box is 1.8 m down the inclined plane. 

I got Part A, need help with B and C 

What is the work Ww done on the box by the weight of the box? 
Express your answers in joules to two significant figures. 

W=1.8J 

B)What is the work Wn done on the box by the normal force?