why the centre of pressure is below the centre of gravity for a submerged plane
Answers
Answer:
Center of pressure is in general below centroid since pressure increases with depth. Center of pressure is determined by equating the moments of the resultant and distributed forces about any arbitrary axis.
NOW FIRST BRAINLIEST MY ANSWER AND LIKE PLEASE
Answer:
Explanation:
For simplicity, let's assume the surface is a flat rectangular surface and also the surface is of uniform mass density, hence its centre of mass will be at the centroid of the surface.
When it is immersed in a fluid, it is subjected to non-uniform pressure as pressure increases with depth. Now the centre of pressure is that point about which the torque of pressure load is zero. As the pressure load is higher at deeper points, pressure load on the lower half of the rectangular surface will be higher than the pressure load on the upper half. Which means, the moment of pressure loads about the geometric centre i.e. centroid of the surface or the centre of mass will NOT be zero, which means centre of mass is not same as centre of pressure.
Torque balance can be written as f1*d1 = f2*d2 where d1 and d2 are the distance of f1 and f2 respectively from the point about which torques are being calculated. In case of pressure, let's say f1 is the pressure load on lower portion of surface and f2 on upper portion. As pressure is higher in lower portion, f1 is higher than f2. Hence for torque balance, d1 should be lesser than d2, which means the point about which moment needs to be taken i.e. centre of pressure should be deeper than the centre of mass.
Of course in one condition both centre of mass and centre of pressure are coincident which is when the surface is horizontal.