Question

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 `15 (kg)/s^2`, what is the minimum value of the surface's coefficient of static friction?

Answer 1

`mu=0,085`

Explanation:

`F=u_k*Delta x`

`u_k=15 " "(kg)/s^2`

`Delta x=5/6 " "m`

`F=15*5/6=75/6=25/2" N"`

`F_f=mu* N"( Friction Force)"`
`mu:"coefficient of static friction"`
`N:"normal force to the contacting surfaces"`
`"we can write "N=m*g" (The Newton's third law)"`

`F=F_f`
`"m:15 kg"`
`25/2=mu*15*9,81`

`25=2*15*9,81* mu`

`25=294,3*mu`

`mu=25/(294,3)`

`mu=0,085`