Question

Suppose the North American plate is moving away from the Eurasian plate at a rate of 2 cm per year. The eastern-most point of North America is currently 1,184 km away from the western-most point of Europe.
Approximately how far apart were North America and Europe 200,000 years ago?

Answer 1

The correct answer is - 1,180 km.

North America and Europe move away from one another, though the two plates, the North American and Eurasian are merging together on the other side. Since the rate of moving away is 2 cm per year, and the current distance is 1,184 km between North America and Europe, the distance between them 200,000 years ago was 1,180 km.

To get to the result we only need to multiply the number of years with the annual movement

2 x 200,000 = 400,000

Than divide the result with 100,000, as that is how much cm are in one km

400,000 / 100,000 = 4

And we get 4 km, in this case 4 km less, thus the distance between the two, 200,000 years ago, was 1,180 km.