Each of two small spheres is charged positively, the total charge being 52.6 µC. Each sphere is repelled from the other with a force of 1.19 N when the spheres are 1.94 m apart. Calculate the charge on each spher

Respuesta :

Answer:

[tex]12.4 \mu C, 40.2 \mu C[/tex]

Explanation:

The electric force between the two spheres is given by

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

where

k is the Coulomb's constant

q1, q2 are the two charges

r is the distance between the spheres

Here we know

F = 1.19 N

r = 1.94 m

So we can solve to find [tex]q_1 \cdot q_2[/tex]:

[tex]q_1 \cdot q_2 = \frac{Fr^2}{k}=\frac{(1.19)(1.94)^2}{9\cdot 10^9}=4.98\cdot 10^{-10} C^2 =[/tex] (1)

We also know that the sum of the two charges is

[tex]q_1 + q_2 = 52.6 \mu C = 52.6\cdot 10^{-6}C[/tex] (2)

So we have a system of 2 equations; from (1) we get

[tex]q_1 = \frac{4.98\cdot 10^{-10}}{q_2}[/tex]

and substituting into (2)

[tex]\frac{4.98\cdot 10^{-10}}{q_2}+ q_2  = 52.6\cdot 10^{-6}C\\\rightarrow q_2^2 -52.6\cdot 10^{-6} q_2 + 4.98\cdot 10^{-10} =0[/tex]

which has two solutions:

[tex]q_1 = 40.2\cdot 10^{-6} = 40.2 \mu C\\q_2 = 12.4\cdot 10^{-6} = 12.4 \mu C[/tex]

Answer:

q1= 4.26×10^-6C

q2= 1.0×10^-6C

Explanation:

q1+q2= 5.26×10^-6C

F=1.19N

F= kq1q2/r^2 =1.19

q1q2= (1.19)(r^2/k)

q1q2= 1.19×(1.94^2)×8.99×10^9=4.026×10^-10C^2

q2= 5.26×10^-6 -q2 ....eq1

q1q2=4.026×10^-10 .....eq2

Put eq1 into eq2

q1(5.26×10^-6)- q1=4.026×10^-10

5.26×10^-6q1-q1^2-4.026×10^-10

q1^2-(5.26×10^-6)q1 +4.026×10^-10

Using almighty formular to solve the quadratic equation

= 5.26×10^-6 +-sqrt(5.26×10^-6)^2 -4(4.026×10^-10) /2

q1=5.26×10^-6 +-sqrt(1.065x10^-11)/2

q1= (5.26×10^-6 )+-3.26×10^-6/2

q1= (2.26×10^-6) + 3.26×10^-6/2

q1= 4.26×10^-6C

q2= (5.26×10^-6 ) -(3.26×10^-6)/2

q2= 1.0×10^-6C