Question

An electric field is measured at 3.00×105 N/C at a distance from a source point charge of 3.00×10−6 C. How far is the point from the source charge?

0.09 m
0.30 m
0.36 m
0.60 m

Answer 1

im not sure where to begin :/

Answer 2

You must use the formula

\(E=k\frac{Q}{r^2}\)
where k=Coulomb's constant
E=Electric field in N/C
Q=Point charge in C
r=radius in m

Plugging in the values

\(3.00\times10^5~\text{N/C}=k\frac{3.00\times10^{-6}}{r^2}\)

You can use algebra to isolate r

Answer 3

Did you understand it yet?

for 'k' you might need to get that online or on your calculator