An object with a mass of 18 kg is lying on a surface and is compressing a horizontal spring by 40 cm. If the spring's constant is 4 (kg)/s^2, what is the minimum value of the surface's coefficient of static friction?

1 Answer
Dec 28, 2017

The coefficient of static friction is =0.01

Explanation:

The mass is m=18kg

The compression of the spring is x=0.4m

The spring constant is k=4kgs^-2

The reaction of the spring is R=kx=4*0.4=1.6N

The acceleration due to gravity is g=9.8ms^-2

The normal reaction of the object is N=mg=18*9.8=176.4N

The coefficient of static friction is

mu_s=R/N=1.6/176.4=0.01