Addition of forces (resultant force)

• Parallel forces
  • 
  • 
• Non-parallel forces
  • Triangle method (start at different points)
    
  • Parallelogram method ( start at the same points)
    
• Perpendicular forces (Phytagorean Theorem)
  

a) Stationary @ constant velocity
\(R=mg\, cos \,\alpha\\ Fg=mg\, sin\, \alpha\)

b) Acceleration
\(mg\,sin\,\alpha-Fg=ma\)