A cylindrical disk of wood weighing 45.0 N and having a diameter of 30.0 cm floats on a cylinder of oil of density 0.850 g>cm3 (Fig. E12.19). The cylinder of oil is 75.0 cm deep and has a diameter the same as that of the wood. (a) What is the gauge pressure at the top of the oil column

665.25 Pa

Explanation:

Given data :

Weight of the disk, w = 45 N

Diameter, d = 30 cm

                    = 0.30 m

Therefore, radius of the disk,

   = 0.15 m

Now, area of the cylindrical disk,

∴ The gauge pressure at the top of the oil column is :

      = 665.25 Pa

Therefore, the gauge pressure is 665.25 Pa.