A tiny object carrying a charge of +40 μC and a second tiny charged object are initially very far apart. If it takes 49 J of work to bring them to a final configuration in which the +40 μC object i is atx = 1.00 mm, y = 1.00 mm, and the other charged object is at x = 1.00 mm, y = 3.00 mm (Cartesian coordinate system), find the magnitude of the charge on the second object. (k = 1/4πε 0 = 8.99 × 109 N · m2/C2)
a. 1.36 μC
b. 0.27 μC
c. 0.54 μC
d. 0.54 μC

Respuesta :

Answer:

Option b. 0.27 μC                        

Explanation:

By definition, Coulomb's law quantifies the amount of force between two stationary, electrically charged particles:    

[tex]F= K\frac{q_{1}q_{2}}{d^{2} }[/tex]    (1)                    

To calculate q₂, we have to find the distances between the charges:

[tex]d=\sqrt{(x_{2}-x_{1})^{2} + (y_{2}-y_{1})^{2}}[/tex]   (2)      

[tex]d=\sqrt{(1-1)^{2} + (3-1)^{2}}[/tex]  

[tex]d=\sqrt{(0)^{2} + (2)^{2}}[/tex]

[tex]d= 2 mm}[/tex]  

   

And now, we need to calculate the electrostatic force, by using the relation between force and electric potential:

[tex]F= \frac{U(x)}{d}[/tex]   (3)

[tex]F= \frac{49J}{2*10^{-3}m}[/tex]    

[tex]F= 24500 N}[/tex]      

 

Finally, we calculate the magnitude of the charge on the second object, using the ecuation (1):

[tex]F= K\frac{q_{1}q_{2}}{d^{2} }[/tex]

[tex]q_{2}=\frac{F*d^{2}}{K*q_{1}}[/tex]  

[tex]q_{2}=\frac{24500N*(2*10^{-3}m)^{2}}{8.99*10^{9}Nm^{2}C^{-2}*40*10^{-6}C }[/tex]  

q₂ = 2.72 × 10⁻⁷C = 0.27 μC                                          

So, the answer is the option b. q₂ = 0.27 μC

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