Concept:The problem uses Bernoulliās principle for the flow of liquid from a pipe when pressure changes.Explanation:Initially, the liquid is at rest inside the closed pipe, so the initial velocity is v1ā=0.The initial gauge pressure is P1ā.After the valve is opened, the pressure becomes P2ā and the liquid flows out with speed v2ā.Applying Bernoulliās equation between the two points:P1ā+21āĻv12ā=P2ā+21āĻv22āSince v1ā=0, this simplifies to:P1ā=P2ā+21āĻv22āRearranging gives:21āĻv22ā=P1āāP2āTherefore, the speed of water flowing out is:v2ā=Ļ2(P1āāP2ā)āāAnswer:The correct option is C: [Ļ2(P1āāP2ā)ā]1/2.