题目10单选题
如图所示,有一沿垂直设置的等截面弯管,截面积为A,弯头转角为<img src="https://tihai-oss-cloud.itihey.com/img/77464113d59de91a0aa79b00d41997e6.png">,进口截面1-1与出口截面在2-2之间的轴线长度为L,两截面之间的高度差为△Z,水的密度为ρ,则作用在弯管中水流的合外力分别为( )<img src="https://tihai-oss-cloud.itihey.com/img/d3126839d5c3947a90ef8c07897dd1cc.jpg">A. <img src="https://tihai-oss-cloud.itihey.com/img/15a716db756e16693358d4a6d66186ac.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/9071c126cf6193fccefa410e28819bcf.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/3fefef50c5f20a880e35070bca15af85.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/88abd2ad5eadd8e19b0ae8308eeb2e02.png">