Answer:
tanΘ
Explanation:
Let gravitational acceleration be g. When the avalanche starts to occur, the gravity force that is parallel to the slope is the same as friction force.
Gravity force that is parallel to the slope can be written as:
G = mgsinΘ
The friction force is the product of normal force and coefficient:
[tex]F_f = N\mu[/tex]
where normal force N is the gravity in the direction perpendicular to the slope
[tex]F_f = \mu mgcos\theta[/tex]
As stated before, gravity force that is parallel to the slope is the same as friction force:
[tex]G = F_f[/tex]
[tex]mgsin\theta = \mu mgcos\theta[/tex]
[tex]\mu = sin\theta / cos\theta = tan\theta[/tex]