Question
The electrical resistance of a wire waves directly as its length & inversely as the square of its diameter if a wire 30m long and 0.75mm in diameter has a resistance of 25ohms , find the length of a wire of the same material whose resistance is 30ohms whose diameter is 1.25mm respectively
Answers
Even not remembering my physics, we can form the equation, since the relationship is given..
R = k L/d^2
25 = k(30)/.75^2
25 = k(30)(16/9)
k = 9(25)/((16)(30)) = 15/32
R = (15/32)L/d^2
plug in the 2nd set of numbers
30 = (15/32) L /1.25^2
finish it up by solving for L
R = k L/d^2
25 = k(30)/.75^2
25 = k(30)(16/9)
k = 9(25)/((16)(30)) = 15/32
R = (15/32)L/d^2
plug in the 2nd set of numbers
30 = (15/32) L /1.25^2
finish it up by solving for L