Chapter 19, Problem 37A

How much force is needed to push a nearly weightless but rigid 1-L carton beneath a surface of water?

To determine

The force needed to push a nearly weightless rigid carton beneath a surface of water.

Answer to Problem 37A

The force needed to push a nearly weightless rigid carton beneath a surface of water is $9.8\text{ N}$ .

Explanation of Solution

Given:

The weight of carton is $1\text{ L}$ .

Formula used:

The expression for force is

  $F=mg$

Here, $m$ is the mass and $g$ is the acceleration due to gravity.

Calculation:

Consider the 1 L carton will displace 1 L of water and the mass of $1\text{ L}$ of water as $m=1\text{ kg}$ .

Consider the acceleration due to gravity as $g=9.8\text{m}/{\text{s}}^{\text{2}}$ .

The force needed to push a nearly weightless rigid carton beneath a surface of water is,

  $\begin{array}{l}F=mg\\ F=\left(1\text{ kg}\right)\times \left(9.8\text{m}/{\text{s}}^{\text{2}}\right)\\ F=9.8\text{ N}\end{array}$

Conclusion:

Thus, the force needed to push a nearly weightless rigid carton beneath a surface of water is $9.8\text{ N}$ .