Question

Propose a force standard different from the example of a stretched spring discussed in the text. Your standard must be capable of producing the same force repeatedly.

Short answer

An example of a force standard capable of producing the same force repeatedly is the force generated through the application of Pascal’s law.

Step-by-step solution

Introduction of force

When force is applied to a body, it has both the magnitude of the force as well as the direction of application of force. Force is responsible for the movement of the object it is applied on.

Example of force standard capable of producing the same force repeatedly

Pascal’s law can be employed to create a force standard.According to Pascal’s law, for a liquid at rest, the difference in pressure between two points depends only on the vertical height difference between the points.

A simple force standard can be constructed by connecting two identical beakers of the known cross-sectional area for measuring the change in volume of the liquid, as shown in the figure.

When the force is applied from the end A, the volume of the liquid in beaker B is increased

Calculate the difference in pressure in the two beakers,

$$\begin{gathered} \mathit{P}\mathbf{=}\mathit{p}\mathit{g}\mathit{h} \\ \frac{\mathbf{F}}{\mathbf{A}}\mathbf{=}\mathit{p}\mathit{g}\mathit{h} \\ \mathit{F}\mathbf{=}\mathit{p}\mathit{g}\mathit{h}\mathit{A} \\ \mathit{F}\mathbf{=}\mathit{p}\mathit{g}\mathit{V} \end{gathered}$$

Here,

• $\mathit{P}$is the pressure

• $\mathit{p}$is the density

• localid="1654157068256" $\mathit{h}$is the height

• localid="1654157202024" $\mathit{F}$is the force

• $\mathit{A}$is the area

• $\mathit{V}$is the volume

• $\mathit{g}$is the acceleration due to gravity

The volume of liquid can be measured when the density of the liquid is known. Hence, this method is suitable for measuring the applied force.