# Use the following information to calculate the coefficient of Static Friction between the shoe and the plank.

80 views
Mass of Shoe: 0.80kg

Angle of Elevation of the Plank: 11 degrees
First find the normal force the surface of the plank exerts on the shoe $N=mgcos(11^\circ)$.
The maximum frictional force which equals the x component of gravity $f=\mu N=mgsin(11^\circ)$.
This will give you the coefficient $\mu$.