Chapter 24, Problem 56A

(a)

To determine

To Plot: Force as a function of distance.

Explanation of Solution

Given:

  

Graph:

  

(b)

To determine

Whether the force follows inverse square law.

Explanation of Solution

Given:

  

Formula used:

As per inverse square law, the physical quantity should vary inversely with square of the distance.

Calculations:

Pick any two values of force and compare them. Then compare the ratio of inverse of corresponding square of the distances.

  $\begin{array}{l}{F}_1=0.4\text{N},d_1=1.2\text{cm}\\ F_2=0.13\text{N},d_2=1.4\text{cm}\\ \frac{F_1}{F_2}=\frac{0.4}{0.13}=3.08\\ \frac{d_2{}^2}{d_1{}^2}=\frac{{1.4}^2}{{1.2}^2}=1.36\end{array}$

The two ratios do not match and thus, this force does not follow inverse square law.