Chapter 22, Problem 70EAP

In Problems 69 through 72 you are given the equation(s) used to solve a problem. For each of these,

a. Write a realistic problem for which this is the correct equation(s).

b. Finish the solution of the problem.

$\begin{array}{l}69.\frac{(9.0\times {10}^{9}N{m}^2/C^2)\times N\times (1.60\times {10}^{-19}C)}{{(1.0\times {10}^{-6}m)}^2}\\ \end{array}$

$=1.5\times {10}^{6}N/C$

$70.\frac{(9.0\times {10}^{9}N{m}^2/C^2)q^2}{{(0.0150m)}^2}$

$71.\frac{(9.0\times {10}^{9}N{m}^2/C^2)(15\times {10}^{-19}C)}{r^2}=54,000N/C$

$72.{\displaystyle \underset{}{\overset{}{\sum }}Fx=2\times }\frac{(9.0\times {10}^{9}N{m}^2/C^2)(1.0\times {10}^{-9}C)q}{{((0.020m)/\sin {30}^o)}^2}\times \cos {30}^o$

$=5.0\times {10}^{5}N$

${\displaystyle \sum Fy=0N}$