Tectonic plates are large segments of the Earth's crust that move slowly. Suppose that one such plate has an average speed of8.1cm/year.(a)What distance does it move in 1 s at this speed? m(b)What is its speed in kilometers per million years? km/million years

The North American and European continents are moving apart at a rate of about 3 cm/y. At this rate how long will it take them to drift 680 km farther apart than they are at present?