Answer:
55.3 N, 223.3 N
Step-by-step explanation:
First of all, we can find the angle of the inclined plane.
We have:
L = 5 m the length of the incline
h = 1.2 m is the height
We also have the relationship

where
is the angle of the incline. Solving for the angle,

Now we can find the components of the weight of the box, which is the force that the box exerts on the plank. Calling W = 230 N the weight of the box, we have:
- Component parallel to the incline:

- Component perpendicular to the incline:
