A three hinged semi-circular arch of radius 'R' carries a uniformly distributed load 'W' per unit run over the whole span. The horizontal thrust will be
1
W R
2
\(\frac{{{\rm{WR}}}}{{\rm{2}}}\)
3
\(\frac{{{\rm{4WR}}}}{{{\rm{3\pi }}}}\)
4
\(\frac{{{\rm{2WR}}}}{{{\rm{3\pi }}}}\)