Determine the force of interaction between 2 electric charges q1= 1x10-6 C and q2= 2x10-6 C at the distance r = 2 m.
I think the formula is F=kq1*q2/r2? How do I find k?
You either look k up
k = 9 * 10^9 N m^2/C^2
or you know it is
1/(4 pi eo)
and you know eo = 8.8 * 10^-12 C^2/(N m^2)
You do not find k, you memorize it in SI units.
k= 8.987E9 N.m^2/C^2
To find the value of k, you need to know the value of the Coulomb's constant (k). Coulomb's constant is given by the equation:
k = 9 x 10^9 Nm^2/C^2
Once you know the value of k, you can substitute it into the formula F = kq1q2/r^2 to calculate the force of interaction between the two charges.
In this case, the value of k is given as 9 x 10^9 Nm^2/C^2.
Now let's calculate the force of interaction between the two charges:
F = k * q1 * q2 / r^2
F = (9 x 10^9 Nm^2/C^2) * (1 x 10^-6 C) * (2 x 10^-6 C) / (2 m)^2
F = (9 x 10^9 Nm^2/C^2) * (1 x 10^-6 C) * (2 x 10^-6 C) / 4 m^2
Now multiply the values:
F = (9 x 2 x 1 x 10^9 x 10^-6 x 10^-6) / 4 N
F = 18 x 10^9 x 10^-6 x 10^-6 / 4 N
F = 18000 x 10^-6 x 10^-6 / 4 N
F = 18000 x 10^-12 / 4 N
F = 18000 / 4 x 10^-12 N
F = 4500 x 10^-12 N
So the force of interaction between the two charges is 4500 x 10^-12 N.