Question 820341
The resistance R of a copper wire varies directly with its radius r and inversely proportional to the square of its length
: 
This is totally wrong
It should read
"The resistance R of a copper wire varies directly with its length L, and inversely proportional to the square of the radius."

The rest of this doesn't make much sense either. A wire with a .4 meter radius?

 If the resistance of a 5 meter wire is .8 ohm and its radius is .4 meter, then determine the length of the wire if its resistance is .3 ohm and its radius is .9 meter



1. If the resistance of a 5 meter wire is .8 ohm and its radius is .4 meter, then determine the length of the wire if its resistance is .3 ohm and its radius is .9 meter