Pressure and force on a small plane area Pressure on plane P mall plane area da Pressure at small plane P=pg h Force on small plane dF=px da=pghda Depends on vertical depth h below surface Force dF= px plane area P and df perpendicular to planePressure and force on a small plane area Pressure at small plane : P =  g h Force on small plane dF = P x dA =  g h dA P depends on vertical depth h below surface Force dF = P x plane area P and dF perpendicular to plane  Pressure on plane P h Small plane area dA