8. An open tank has a vertical partition and on one side contains gasoline with a density p=700 kg/m³ at a depth of 4 m, as shown in Figure 8. A rectangular gate that is 4 m high and 2 m wide and hinged at one end is located in the partitipn. Water is slowly added to the empty side of the tank. At what depth, h, will the gate start to open? Partition Water Stop Hinge 4 m Gasoline Figure P8