# An object with a mass of 15 kg is lying still on a surface and is compressing a horizontal spring by 5/6 m. If the spring's constant is 24 (kg)/s^2, what is the minimum value of the surface's coefficient of static friction?

The horizontal force exerted on the object = force con.x compression = $24 \cdot \frac{5}{6}$=20 N
Now $\mu m g =$ the force applied
coefficient of static friction,$\mu =$ $\frac{20}{m g}$= $\frac{20}{15 \cdot 9.8}$ = 0.1361