Line Charge Density of 30uC/7.0m Wire: Answer & Explanation

[tnutty]

Homework Statement

A straight wire 7.0m long carries 30uC distributed uniformly over its length.
What is the line charge density on the wire?

_____ uC/m

Homework Equations

A) E = 2k/lamda /

B) E = kq/r

some other ones?

The Attempt at a Solution

I sub B into a, and got q/2 = 15. But its not correct. Which formula do I use?

 

[PhaseShifter]

Neither.

Hint: You're given charge and length and asked to calculate charge per unit length...shouldn't be too hard to figure this one out ;)

 

[tomcue]

As a scientist, it is important to use the appropriate formula that is relevant to the given scenario. In this case, the correct formula to use is E = lamda/2(pi)epsilon_0, where lamda represents the line charge density, and epsilon_0 is the permittivity constant. Plugging in the given values of 30uC for charge and 7.0m for length, we can calculate the line charge density to be 4.27 uC/m. It is important to carefully select the appropriate formula and units to ensure an accurate calculation.