قوة الاحتكاك

d = Distance (0.5 m)

t = Time (s)

V = Velocity (\frac{m}{s})

G = Gravity (\frac{m}{s^2})

Θ = Inclination Angle (20)

μ = Friction Coefficient

μ = \frac{d*g*sin(Θ)-\frac{1}{2}*v^2}{d*g*cos(Θ)}