(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I have some information about a 2H pencil. There is a current of 0.008 amps and 3.8 volts going through the pencil. The length of the pencil was 16cm and the diameter of the core was 2mm. Calculate the percentage of graphite in the pencil.

2. Relevant equations

ohms law

V= I. R

resistivity

R=(ρ.L)/(A)

3. The attempt at a solution

i calculated the resistance to be 47.5 ohms, using ohms law.

i then substituted of my known values into the resistivity formula

R=47.5

A=3.14159E-06 meters squared

L=0.16meters

47.5 =(ρ.0.16)/(3.14159E-06 )

ρ=0.00093266 ohm meters

Is this correct so far?

Also what is the resistivity of graphite ??????

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Finding amount of graphite in a Pencil

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