# Resistance question

1. Feb 12, 2009

### corey7

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

A rectangular solid made of carbon has sides of lengths 5.5 cm, 11.0 cm, and 22.0 cm, lying along the x, y, and z axes, respectively (Fig. 18-35). Assume the resistivity of carbon is ρ = 3.0 multiplied by 10-5 ·m.

http://www.webassign.net/giancoli5/18_32alt.gif" [Broken]

Figure 18-35

(a) Determine the resistance for current that flows through the solid in the x-direction.

(b) Determine the resistance for current that flows in the y-direction.

(c) Determine the resistance for current that flows in the z-direction.

2. Relevant equations

R = ρL/A

3. The attempt at a solution

Okay I think the only thing thats screwing me over is the area. I dont know what to multiply with what in order to get the correct area. For the x I've tried multiplying the 5.5 and 11.0 but wrong answer. *sigh*

Thanks alot to whoever can help :D

Last edited by a moderator: May 4, 2017
2. Feb 13, 2009

### LowlyPion

The area is taken in the direction of the current flow.

In the x direction that's A=y*z and L = x

Be careful of units. cm = .01 m.