Lets say that i have 2 different types of containers, one cuboidal and another one conical. and lets say both these are massless and fully contain water.
**1.**In the cuboidal one the pressure exerted by liquid column at base is Densitygheight.This multiplied by Area of base will give the force exerted on base.As the container is massless total downwards force is also same.And now by calculating volume and density of liquid , we can find mass of liquid and multiplying by 'g' gives total downwards force.In this case total downward force calculated by both the methods is equal.
**2.**In the conical container, the total downwards force calculated using densitygheight and multiplying by conical container's base area is 3 times greater than the force calculated using volume and density relationship(As the volume is 1/3*height*area).Why is it different, which method is correct to calculate downward force? Why is it so?