Stel: Straal leuning is R
Stel: Per omwenteling van de trap = stijging van 1,5 meter.
Stel: Totaal aantal omwentelingen =5,5=
\(5,5 2 \pi=11\pi radialen\)
1,5 meter stijging per omwenteling is
\(\frac{1,5}{2\pi}\)
meter stijging per 1 radiaal.
\(\vec{r_{t}}=x_t\hat{i}+y_t\hat{j}+z_t\hat{k}\)
\(\vec{r_{t}}=R\cos t\hat{i}+R\sin t\hat{j}+\frac{1,5}{2\pi}t\hat{k}\)
Totale Lengte leuning is:
\(L=\int_{0}^{11\pi}\sqrt{{(\frac{dx}{dt})}^2+{(\frac{dy}{dt})}^2+{(\frac{dz}{dt})}^2} dt\)
\(L=\int_{0}^{11\pi}\sqrt{R^2+{(\frac{1,5}{2\pi})}^2 } dt\)
Stel: R=2 meter
\(L=\sqrt{R^2+{(\frac{1,5}{2\pi})}^2} (11\pi -0)=11\pi\sqrt{4+{(\frac{1,5}{2\pi})}^2}\)