Question

PLEASE HELP!! PHYSICS QUESTION-DOES ANYONE KNOW HOW TO DO THIS WITH THE WORKING OUT?!?

Answer 1

Answer:

$1.5 \Omega$

Explanation:

The resistance of a piece of wire is given by

$R=\frac{\rho L}{A}$

where

$\rho$ is the resistivity of the material

L is the length of the wire

A is the cross-sectional area

In this problem, we have

$\rho = 3.3\cdot 10^{7} m$

L = 7.0 m

The diameter of the wire is 0.14 cm, so the radius is 0.07 cm, therefore the cross sectional area is

$A=\pi r^2 = \pi (0.07)^2=0.0154 cm^2 = 0.0154\cdot 10^{-4} m^2$

Therefore, the resistance is

$R=\frac{(3.3\cdot 10^{-7})(7.0)}{(0.0154\cdot 10^{-4})}=1.5 \Omega$