Answer:
μ = 0.48
Explanation:
To solve this problem we must make a free body diagram locating each of the respective forces on the boxes.
We must pay special attention that the body is moving at a constant speed, therefore there is no acceleration, and the sum of forces is equal to zero.
Attached is an image with the sum of forces and the equations of the sum of forces on the x & y axes.
The solution of all equations can be seen, in the attached image.
