The speed factor for the speed above 100 km/h given by German formula, which is adopted in Indian railways after 1966 is:
1
\(\frac{V}{{\sqrt[3]{\mu }}}\)
2
\(\frac{{4.5{V^2}}}{{{{10}^5}}} - \frac{{1.5{V^3}}}{{{{10}^7}}}\)
3
\(\frac{{4.5{V^3}}}{{{{10}^7}}} - \frac{{1.5{V^3}}}{{{{10}^5}}}\)
4
\(\frac{{{V^2}}}{{30000}}\)