Distance between two concentric circles?

The Earth Circumference measures 40,000,000 meters.
If we wrap a string around it, then add a 1 meter piece to it and we wrap it around the Earth again: What will be the distance between the two concentric circles?
Update: Good job, mathman and hunnebe...
Now if instead of wrapping the string around the the Earth, you wrap it around a dime, then add 1 meter, what would be the distance between the circumference of the dime and that of the new circle?
I know you both can figure it out, it's also 0.16 meters.
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