Two vessels have the same base area but differnent shapes. The first vessel takes twice the vloume of water that the second vessel requires to fill up to a paricular common height . Is the force exerted by water on the base of the vessel the same in the two case? If so, why do the vessels filled with water to that same height give different reading on a weighting scale ?

Explanation

Pressure (and therefore force) on the two equal base areas are identical. But force is exertd by water on the sides of the vessels also, which has a non-zero vertical component when sides of the vessel are not perfectly normal to the base. This net vertical component of force by water on the sides of the vessel is g reater for the first vessel than the second. hence, the vessels weigh different even when the force on the base is the same in the two cases.