Free Body Diagram of a Mass on a Slope

This freebody diagram shows the same forces that work on a slab of snow on a mountainside.

The slab has a mass of m. The slope has an angle of (alpha). The frictional force is (mu). The avalanche starts when ax > 0.

F1 + F2 + F3 = m a (Newton's 2nd Law) g = gravitational acceleration
   
F1 = force of gravity acceleration in y direction:
F2 = normal force ay = 0
F3 = frictional force  
   
in x direction:  
m ax = F1x - F3  
F1x = F1sin (alpha)  
F1 = m g  
F3 =  (mu) m g cos (alpha)  
   
m ax = (m g sin (alpha)) - ((mu) m g cos (alpha))  
ax = g (sin (alpha) - (mu) cos (alpha))  
   
   
   
   
   
   

 

*How An Avalanche Forms
*Loose Snow Slide
*Slab Slide
*Free Body Diagram
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