Water is flowing through a gradual constriction in a pipe. The upstream diameter of the pipe is d1=4cm, and the downstream diameter is d2=2cm. The pressure drop across the contraction is deltaP=50kPa, and the flow rate is Q=3 l/s. A pressure gauge measures a pressure downstream from the contraction of P2=100kPa. What force does the water exert on the area of pipe contraction?