A jet of water (area $${A_j},$$ velocity $${V_j},$$ density $$\rho $$ ) impinges horizontally on a curved vane which deflects the jet through $${60^0}$$ upwards. If the vane travels horizontally at a speed $$'u'$$ find
(a) the force experienced by the vane, and
(b) the power developed by the vane.