Answer:
0.17
Explanation:
Draw a free body diagram. There are five forces on the box:
Weight force mg pulling down
Normal force Fn pushing up
Applied force 52 N pulling to the left
Applied force 125 N pulling to the right
Friction force Fnμ pulling to the left
Sum of the forces in the y direction:
∑F = ma
Fn − mg = 0
Fn = mg
Fn = (45)(9.8)
Fn = 441
Sum of the forces in the x direction:
∑F = ma
125 − 52 − Fnμ = 0
Fnμ = 73
μ = 73 / Fn
μ = 73 / 441
μ = 0.17
