Question

A boat made of wood is floating in the water with two boys in it. The volume of water displaced is 0.125 m³ . What is the upthrust exerted by water on the boat? How do the two answers compare? Why is this so?

Answer 1

Step 1: Given Data

The volume of the box,$V$$=50cm\times 50cm\times 50cm$

$$\begin{gathered} =0.5m\times 0.5m\times 0.5m \\ =0.125m^3 \end{gathered}$$

The density of water, $p$$=1000Kg/m^3$

acceleration due to gravity,$g=10m/s^2$

Upthrust, $F_B$

Step 2: Relation between the upthrust and density

$F_B=pVg$

Step 3: Finding the value of the upthrust

$$\begin{gathered} F_B=pVg \\ =1000\times 0.125\times 10 \\ =1250N \end{gathered}$$

Hence, the upthrust is$1250N$. Since upthrust depends on the weight of the liquid displaced.

Hence, upthrust will be the same in both cases as in both the case weight of the liquid displaced is the same.