球取出后,水形成一个圆台,下底面半径r=√3R,设上底面半径为r',
则高h'=(r-r')tan60°=√3(√3R-r'),
∴5π/3R3=π/3h'(r2+r'2+rr'),
∴5R3=√3(√3R-r')(r'2+√3Rr'+3R2),∴5R3=√3(3√3R3-r'3),
解得r'=∛(4/√3)R=√(6&16/3)R,
∴h'=(3-∛12)R.
答:容器中水的高度为(3-∛12)R.