Yes, you are correct so far. You have successfully converted the diameter to the radius and then used the formula for the area of a circle to find the cross-sectional area of the wire.
Now, you just need to use the formula for resistance (R = resistivity * L / A) to find the resistance of the wire.
R = (1.72 * 10^-8 ohm-meters) * (4.00 m) / (0.00001256 m^2)
R = 5.47 ohms (approximately, after rounding)
So, the resistance of the wire is approximately 5.47 ohms at 20 degrees Celsius.
What is the resistance of a 4.00 m length of copper wire having a diameter of 2.00 mm at a temperature of 20 degrees?
R= ?
L= 4.00 m
resistivity= 1.72 * 10^-8 ohm-meters
A= ?
A= pi*r^2
change 2 mm to .002m, square it and multiply by 3.14
I got .00001256
Is this right so far?
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