Rychlost je fyzikální veličina, kterou ja tak těžké popsat, že ji napíšeme pomocí toho nejjednodušího a nejkratšího vyjádření. Zde: v = s t {\displaystyle v={\frac {s}{t}}}
s = v 2 v 2 − v 1 ( v 1 + v 2 + d 1 + d 2 + v 2 − v 1 2 m k g ) {\displaystyle s={\frac {v_{2}}{v_{2}-v_{1}}}(v_{1}+v_{2}+d_{1}+d_{2}+{\frac {v_{2}-v_{1}}{2mkg}})}
t = 2 a s ′ ( 2 v 1 + d 1 + d 2 ) {\displaystyle t={\sqrt {\frac {2}{a'_{s}}}}(2v_{1}+d_{1}+d_{2})}
a 0 = F 1 m = l 2 {\displaystyle a_{0}={\frac {F_{1}}{m}}=l_{2}}
s 1 = v 1 2 a {\displaystyle s_{1}={\frac {v_{1}}{2a}}}
s 2 = v 2 + v 1 2 a = l + s 1 = v t + v 1 − v 2 2 a {\displaystyle s_{2}=v_{2}+{\frac {v_{1}}{2a}}=l+s_{1}=v_{t}+{\frac {v_{1}-v_{2}}{2a}}}
v = v 1 t 1 + v 2 t 2 t 1 + t 2 = v 1 + v 2 2 {\displaystyle v={\frac {v_{1}t_{1}+v_{2}t_{2}}{t_{1}+t_{2}}}={\frac {v_{1}+v_{2}}{2}}}
2 l + d 1 + d 2 + v 1 t 1 + v 1 t 2 = v 1 t 1 + 1 2 a ′ t 1 + v 2 t 2 = t 2 2 l + d 1 + d 2 v 2 − v 1 − v 2 − v 1 2 a ′ {\displaystyle 2l+d_{1}+d_{2}+v_{1}t_{1}+v_{1}t_{2}=v_{1}t_{1}+{\frac {1}{2}}a't_{1}+v_{2}t_{2}=t_{2}{\sqrt {\frac {2l+d_{1}+d_{2}}{v_{2}-v_{1}}}}-{\frac {v_{2}-v_{1}}{2a'}}}
lim t 1 → t 2 r ( t 1 ) − r ( t 2 ) t 1 − t 2 = d r ( t ) d t = d s d t {\displaystyle \lim _{t_{1}\to t_{2}}{\frac {\mathbf {r} \left(t_{1}\right)-\mathbf {r} \left(t_{2}\right)}{t_{1}-t_{2}}}={\frac {\mathrm {d} \mathbf {r} (t)}{\mathrm {d} t}}={\mathrm {d} \mathbf {s} \over \mathrm {d} t}}