A manometer consists of two tubes A and B, with vertical axes and uniform cross- sectional areas 350 mm and 400 mm, respectively. Both tubes are connected to a U-tube C of cross-sectional area 60 mm. Tube A contains a liquid of relative density 0.75; tube B contains one of relative density 0.9. The surface of separation between the two liquids is in the vertical side of C connected to tube A (see Figure 2). Estimate the additional pressure that has to be applied to tube B to cause the surface of separation to rise by 45 mm in tube C. Figure 2 B