Physics equation

[12345678]

Hello, I'm having some problems with this question (sorry if this is in wrong section). 'Calculate the resistance of a uniform wire diameter 0.32mm and length 5.0m. The resistivity of the material =5.0x10^-7'. (R=resistance, p=resistivity, L=length and A=area, #=pie). A=#r^2. r=0.16mm=0.00016m. A=#0.00016^2=8.04*10^-6. R=5(5*10^-7)/8.04*10^-6=0.31 ohms. However, answer=31 ohms- anybody know what I'm doing wrong? Any help will be appreciated

 

[mathmari]

Hello, I'm having some problems with this question (sorry if this is in wrong section). 'Calculate the resistance of a uniform wire diameter 0.32mm and length 5.0m. The resistivity of the material =5.0x10^-7'. (R=resistance, p=resistivity, L=length and A=area, #=pie). A=#r^2. r=0.16mm=0.00016m. A=#0.00016^2=8.04*10^-6 \(\displaystyle \leftarrow \). R=5(5*10^-7)/8.04*10^-6=0.31 ohms. However, answer=31 ohms- anybody know what I'm doing wrong? Any help will be appreciated

\(\displaystyle A=\pi \cdot {0.00016}^2=8.04 \cdot 10^{-8 } \)

Then \(\displaystyle R=\frac{pL}{A}=\frac{5.0 \cdot 10^{-7} \cdot 5.0 }{8.04 \cdot 10^{-​8}}=31 \) ohms.