Find the Charge Needed for a 1.20V Voltage at 5.0m

[NegaChin]

We wish to place a small charged sphere at a distance of 5.0 m from a point in space such that the voltage at that point is 1.20 V. How much charge should be on the sphere (in nC)?

 

[hage567]

What have you tried? What equations do you think you might need?

 

[NegaChin]

I've tried V = kQ/r and V = kQ/r^2. If either of those are right, please respond, and if one of them is, then I feel I'm having conversion errors.

 

[NegaChin]

r is essentially the distance (my teacher has been using 'radius' all this time)

 

[Gear300]

That second equation you're using with the r^2, don't use that one. The one you want to use is the first one. k is a constant and r is the radial distance (the question specifies that as 5.0m). If the voltage at that point is 1.20V, and you know the value of k and r, then just solve for Q.

 

[NegaChin]

The answer comes out in Coulombs, right? How would I convert that to nanoCoulombs? Just multiply by 10^-9?

 

[rootX]

Yea, in coulombs.

u know 1 [nC] = 1E-9 [C]
say you get x coloumb
x [C] * 10^-9 [?]/1[?] ??
you must learn to use those SI units