# PhysicsMechanics- friction

#### Shah 72

##### Member
In a factory, a machine picks up a box by clamping it on both sides. The box of mass 4kg is held clamped on both sides by identical clamps with the contacts horizontal. The machine provides a contact force of 50N with each clamp. Find the minimum coefficient of friction between each clamp and the box for the box not to slip.

#### skeeter

##### Well-known member
MHB Math Helper
have you sketched a free body diagram?

In the vertical direction ...

$\sum f_{s \, max} = mg$

#### Shah 72

##### Member
have you sketched a free body diagram?

In the vertical direction ...

$\sum f_{s \, max} = mg$
Yeah I did that. 40=coefficient of friction ×(50+50).
Coefficient of friction =0.4

#### Shah 72

##### Member
have you sketched a free body diagram?

In the vertical direction ...

$\sum f_{s \, max} = mg$
Thank you so much!