Suppose that the circumference of earth is a perfect circle of exactly 25,000 mi. somebody prepares a wire that is supposed to go around the equator completely but makes it 2 m too long by mistake. if this 2-m-too-long wire were placed around the equator in a perfect circle with the ends of the wire just touching each other, by how much would the wire be off the ground?

The wire will be 31.83 cm off the ground. This result is independent of the circumference of the Earth!!!

Explanation:

The circumference c of a circle with radius r can be obtained with the formula:

If the circumference of the earth is , and the radius of the earth is , we get:

Now, for a circumference 2 meters to long, we get:

we can obtain how much would the wire be off the ground simply by taking the difference of this equations:

So, the wire will be 31.83 cm off the ground. This result is independent of the circumference of the Earth!!!

wavelength divides in half and speed stays the same.