q = sqrt(F r^2/k)
just rearrange Coulomb's Law
The force between two identical charges separated by 1 cm is equal to 90 N. What is the magnitude of the two charges?
4 answers
F = k q1q2/r^2
Rearrange gives;
q = Fr^2/k
= (90)(0.01)^2/8.99 x 10^9
= 1 x 10^-12 C
Rearrange gives;
q = Fr^2/k
= (90)(0.01)^2/8.99 x 10^9
= 1 x 10^-12 C
Find the force of attraction between two equal but opposite charges, of 2x10 C if the distance between them is 25 cm.
F=90
r=1cm=0.01m
k=8.99*10^9
90=(8.99*10^9)(q)^2/0.01m
0.9=(8.99*10^9)(q)^2
1.00*10^10=q^2
q=1.00*10^-5 or -1.00*10^-5
r=1cm=0.01m
k=8.99*10^9
90=(8.99*10^9)(q)^2/0.01m
0.9=(8.99*10^9)(q)^2
1.00*10^10=q^2
q=1.00*10^-5 or -1.00*10^-5
2 answers