Question

Beaker A is filled to the brim with water. Beaker B is the same size and contains a small block of wood that floats when the beaker is filled with water to the brim. Which beaker weighs more?

(a) Beaker A.

(b) Beaker B.

(c) The same for both

Short answer

The correct option is (c) the same for both.

Step-by-step solution

Understanding the weight

The weight can be described as the force that acts on an object which consists of specific matter (mass) due to gravitational acceleration in the vertically downward direction. Weight is dependent on the gravitational acceleration and mass of the object.

Evaluating the weight of the beaker

The weight of the beaker directly depends upon the total pressure at the bottom surface of the beaker. The pressure at the bottom surface of the beaker is given by the expression,

P =( P₀ + ρgh)

Here, P is the total pressure at the bottom of the beakers, P₀ is the atmospheric pressure, g is the gravitational acceleration, ρ is the density of liquid and h is the height up to which the liquid is filled.

Since both beakers have the same size and are filled with the same liquids, then both beakers' weights would be the same/equal.

Thus, from the above analysis, option (c) is correct.