How this calculator works
On the slope, the downhill weight component is reduced by kinetic friction. The sled starts from rest, with constant acceleration on the hill. On level ground the frictional deceleration is mu times gravity. The coefficients can differ between hill and runout. The two published snow references are teaching examples, not universal material constants; measured coefficients are preferable because snow temperature, waxing and surface condition strongly affect glide. Static release friction is not modelled.
Formula
a=g(sin(theta)-mu_hill cos(theta)); v=sqrt(2aL); t=v/a; a_stop=mu_flat g; d_stop=v^2/(2a_stop); t_stop=v/a_stop.
Worked example
With g=10 m/s2, sin(theta)=0.6, cos(theta)=0.8, mu_hill=0.25 and L=8 m, acceleration is 4 m/s2, bottom speed is 8 m/s and descent lasts 2 s. If mu_flat=0.2, stopping takes 4 s and 16 m.
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Frequently asked questions
Why are there only two snow presets?
They have traceable teaching references. Enter measured coefficients for plastic, steel or other snow conditions rather than assuming a universal number.
What if friction is too high to accelerate downhill?
The release-from-rest model has no downhill run and reports an error.
Does the result include air drag or steering?
No. It assumes a straight slope, constant contact friction and no aerodynamic or braking forces.